i need help again and can smb help me with the whole study guide pls !

Answer:

a) 0 seconds.

b) The stunt diver is in the air for 2.81 seconds.

Step-by-step explanation:

Solving a quadratic equation:

Given a second order polynomial expressed by the following equation:

[tex]ax^{2} + bx + c, a\neq0[/tex].

This polynomial has roots [tex]x_{1}, x_{2}[/tex] such that [tex]ax^{2} + bx + c = a(x - x_{1})*(x - x_{2})[/tex], given by the following formulas:

[tex]x_{1} = \frac{-b + \sqrt{\Delta}}{2*a}[/tex]

[tex]x_{2} = \frac{-b - \sqrt{\Delta}}{2*a}[/tex]

[tex]\Delta = b^{2} - 4ac[/tex]

Height of the diver after t seconds:

[tex]h(t) = -4.9t^2 + 12t + 5[/tex]

a) How long is the stunt diver above 15 m?

Quadratic equation with [tex]a < 0[/tex], so the parabola is concave down, and it will be above 15m between the two roots that we found for [tex]h(t) = 15[/tex]. So

[tex]h(t) = -4.9t^2 + 12t + 5[/tex]

[tex]15 = -4.9t^2 + 12t + 5[/tex]

[tex]-4.9t^2 + 12t - 10 = 0[/tex]

Quadratic equation with [tex]a = -4.9, b = 12, c = -10[/tex]. Then

[tex]\Delta = 12^{2} - 4(-4.9)(-10) = -52[/tex]

Negative [tex]\Delta[/tex], which means that the stunt diver is never above 15m, so 0 seconds.

b) How long is the stunt diver in the air?

We have to find how long it takes for the diver to hit the ground, that is, t for which [tex]h(t) = 0[/tex]. So

[tex]h(t) = -4.9t^2 + 12t + 5[/tex]

[tex]0 = -4.9t^2 + 12t + 5[/tex]

[tex]-4.9t^2 + 12t + 5 = 0[/tex]

Quadratic equation with [tex]a = -4.9, b = 12, c = 5[/tex]. Then

[tex]\Delta = 12^{2} - 4(-4.9)(5) = 242[/tex]

[tex]x_{1} = \frac{-12 + \sqrt{242}}{2*(-4.9)} = -0.36[/tex]

[tex]x_{2} = \frac{-12 - \sqrt{242}}{2*(4.9)} = 2.81[/tex]

Time is a positive measure, so we take 2.81.

The stunt diver is in the air for 2.81 seconds.

Answer:

2x + 13

13

Step-by-step explanation:

Albert and Maxim own

x + (x + 13) = 2x + 13 model airplanes together

Albert owns

(x + 13) - x = 13 less model airplanes than Maxim.

Answer:

They own 2x+13 model airplanes together

Albert owns 13 less model airplanes than Maxim

Answer:

I believe it's   A = 0.75j + 9

Step-by-step explanation:

If x or j is the amount of cups of OJ you sell, and you earn $0.75 per cup.

0.75x

The b = 9 which adds to the total amount of money you have

0.75x+9

A is the total money you earn after you sell j cups.

I hope this helps!

Answer:

B. 23,5

Step-by-step explanation:

Answer:

16

Step-by-step explanation:

Jen's class: 10 girls, 15 boys

ratio of girls to boys = 10:15 = 2:3 = 2x:3x

Ed's class

number of boys = 24

ratio of girls to boys = 2x:3x

3x = 24

x = 8

2x = 2(8) = 16

Answer: 16

Answer:

16

Step-by-step explanation:

Answer:

Step-by-step explanation:

2(a + 6b) - 3(a - 2b)

= 2a + 12b - 3a + 6b

= 2a - 3a + 12b + 6b

= - a + 18b (Ans)

Answer:

-a + 18b

Step-by-step explanation:

2(a + 6b) - 3(a - 2b)

Distribute the 2

2a + 12b - 3(a - 2b)

Distribute the 3

2a + 12b - 3a + 6b

Combine like terms

-a + 18b

Solution :

Cost of 1 kg super tea mixture

[tex]$=\frac{1(1600)+5(800)+1(1700)}{1+5+1}$[/tex]

[tex]$=\frac{1600+4000+1700}{7}$[/tex]

[tex]$=\frac{7300}{7}$[/tex]

= 1042.8

≈ 1043

Include of cost blending and packaging.

So, cost of 1 kg is 1043 + 40 = 1083

Cost of packaging of 825 gram super tea = [tex]$\frac{825}{1000} \times 1083$[/tex]

                                                                     = 893.47

Answer:

% increase = 100 x [(new price) - (original price)] / (original price)] = 100 (9.67 - 9.56) / 9.56

% increase ≅ 1.2% (to the nearest tenth)

Answer:

nothing

Step-by-step explanation:

Zero is a number without a value so nothing could be another word for it

Answer:

To make a profit of course

Step-by-step explanation:

it

then

yes

Possibly.

Answer:

a = 45 millimeters

Step-by-step explanation:

In order to solve this, we need to know that for right-angled triangles the following is true:

[tex]c^{2} = a^{2} + b^{2}[/tex] (where c is the hypotenuse and "a" and "b" are the legs)

From the formula above we can conlude that...

[tex]a = \sqrt{c^{2} - b^{2} }[/tex]

Now we just substitute the variable that we know and get that...

[tex]a = \sqrt{c^{2} - b^{2} }\\a = \sqrt{75^{2} - 60^{2} } \\a = \sqrt{5,625 - 3600} \\a = \sqrt{2025} \\a = 45[/tex]

Therefore a = 45millimeters.

Answer:

540m^3

Step-by-step explanation:

find volume of top + volume of bottom

bottom: l*w*h = 16*5*4 =300 m^3

top = area of side times width = area of triangle times width

area of triangle is 1/2*b*h = (6*16)/2 = 48 m^2

multiply by width = 48*5=240m^3

add top and bottom = 300+240=540m^3

Answer:

The associative property allows us to change groupings of addition or multiplication and keep the same value. (a+b)+c = a+(b+c) and (a*b)*c = a*(b*c).

Step-by-step explanation:

in mathematics, either of two laws relating to number operations of addition and multiplication, stated symbolically: a + (b + c) = (a + b) + c, and a(bc) = (ab)c; that is, the terms or factors may be associated in any way desired.

Answer:

Associative

Step-by-step explanation:

Answer:

m = 3 , n = 4

Step-by-step explanation:

Using Section Formula.

[tex]If \ the \ line \ segment \ AB \ where \ A = (x _1, y_1) \ and \ B = (x_2, y_2) \ divided \ by \ P =(x , y) \ in \ the \ ratio \ a : b,\\\\Then \ the \ points \ of \ P \ \\\\x = \frac{ax_2 + bx_1}{a+b} \ and \ y = \frac{ay_2 + by_1}{a+b}[/tex]

   [tex]Here (x_1 , y_ 1 ) = ( -7 , 1 ) \ and \ (x_ 2 , y _ 2 ) = (m , 6)\\\\ratio\ a:b = 3 : 2\\\\Therefore, P (x, y) \\\\x = \frac{3m + (2\times -7)}{5} \ \ \ \ \ \ \ \ \ \ \ [ \ x = -1 \ ] \\\\-1 = \frac{3m - 14}{5}\\\\- 5 = 3m - 14\\\\-5 + 14 = 3m\\\\9 = 3m \\\\m = 3[/tex]

  [tex]y =\frac{3\times 6 + 2 \times 1}{5}\\\\n = \frac{18 + 2}{5} = \frac{20}{5} = 4[/tex]

Answer:

Step-by-step explanation:

1000 gallons - 940 = 60 then divide by the time which gets us 60/10=6

Now we can use this answer to help find out the amount remaining in the tank.

5 minutes = 5x6=30; 1000-30= 970 gallons

20 minutes= 20x6=120; 1000-120= 880 gallons

30 minutes=30x6=180; 1000-180= 820 gallons

27 minutes=27x6=162; 1000-162= 838 gallons

X minutes = 1000-6x

Rate of flow is 6 gallons per minute.

Hope this helps!

Answer: y = 6x

Step-by-step explanation:

Since this is a direct proportion, we will introduce the constant of proportionality here and this will be:

y = kx

Since y = 30 and x= 5,

30 = 5 × k

30 = 5k

k = 30/5

k = 6

Therefore, the equation that connects y to x will be:

y = kx

y = 6x

The equation that connects y to x is y = 6x.

Answer:

XP = 11

Step-by-step explanation:

Given that XZ = 7x + 1 and PZ = 4x − 1

From the diagram, XZ = 2PZ

7x + 1 = 2(4x-1)

7x+1 = 8x - 2

7x - 8x = -2 -1

-x = -3

x = 3

Since XP = PZ

XP = 4x - 1

XP = 4(3) - 1

XP = 12-1

XP = 11

Answer:

-9.25

Step-by-step explanation:

-5.75 - 3.5

-9.25

[tex]\implies {\blue {\boxed {\boxed {\pink {\sf { \:- 9 \frac{1}{4} (or) \:- 9.25 }}}}}}[/tex]

[tex]\large\mathfrak{{\pmb{\underline{\red{Step-by-step\:explanation}}{\red{:}}}}}[/tex]

[tex] - 5 \frac{3}{4} - 3 \frac{1}{2} [/tex]

➺[tex] \: \frac{ - 23}{4} - \frac{7}{2} [/tex]

➺[tex] \: \frac{ - 23}{4} - \frac{7 \times 2}{2 \times 2} [/tex]

➺[tex] \: \frac{ - 23 - 14}{4} [/tex]

➺[tex] \frac{ - 37}{4} [/tex]

➺[tex] \: - 9 \frac{1}{4} [/tex]

➺[tex] \: -9.25[/tex]

[tex]\large\mathfrak{{\pmb{\underline{\orange{Mystique35 }}{\orange{❦}}}}}[/tex]

Answer:

Right Triangle

Step-by-step explanation:

It has a 90 degree angle

The measure of angle OCD from the given figure is 58°.

Given that, the points A, B, C and D lie on a circle Centre O.

A circle is a two-dimensional figure formed by a set of points that are at a constant or at a fixed distance (radius) from a fixed point (center) on the plane. The fixed point is called the origin or center of the circle and the fixed distance of the points from the origin is called the radius.

Here, OC and OB are radius of a circle, then BOC is isosceles triangle

Now, ∠BOC+∠OBC+∠OCB=180°

50°+∠OBC+∠OBC=180°

⇒ 2∠OBC=130°

⇒ ∠OBC=65°

Here, ∠OCD=∠BCD-65°

⇒ x=123-65=58°

Hence, the measure of angle OCD from the given figure is 58°.

To learn more about the circle visit:

https://brainly.com/question/11833983.

#SPJ2

Answer:

£28 : £7

Step-by-step explanation:

sum the parts of the ratio, 4 + 1 = 5 parts

Divide the quantity by 5 to find the value of one part of the ratio

£35 ÷ 5 = £7 , then

4 parts = 4 × £7 = £28

£35 = £28 : £7 in the ratio 4 : 1

Answer:

the cost of Roy's ride is $23.05

Step-by-step explanation:

According to the Question,

Let, Cost of per minute charge is 'x' & Cost Of Per Kilometre charge is y .

⇒ Judy's ride costs $16.75 . but the actual cost after deducting the fixed charge is 16.75-2.55 = $14.20, took 8 minutes & The distance travelled was 10 km. Thus, the equation for the journey is 8x+10y=14.20 ⇒ Equ. 1

⇒ Pat's ride costs $30.35 . but the actual cost after deducting the fixed charge is 30.35-2.55 = $27.80, took 20 minutes & The distance travelled was 18 km. Thus, the equation for the journey is 20x+18y=27.80 ⇒ Equ. 2

Now, on Solving Equation 1 & 2, We get

x=0.4(Cost of per minute charge) & y=1.1(Cost Of Per Kilometre charge)

Now, Roy's ride took 10 minutes & The distance travelled was 15 km . Thus, the cost of Roy's Ride is 10x+15y ⇔ 10×0.4 + 15×1.1 ⇔ $20.5

Hence, the total cost of Roy's ride is 20.5 + 2.55(fixed cost) = $23.05

35°..

can also be 145° but not in this case since the angle is less than 90°

Answer:

(i)unique solution

Explanation:

We solve for x1 thus in the first equation:

x1-3x3=-3

x1-9=-3

x1=-3+9

x1= 6

We solve for a thus in the second equation:

2x1+ax2-x3=-2

2+a2-x3=-2

a2-x3=-4

a2=-4+x3