A radioactive substance decays at a rate of 3.4% per day. If it starts at 200 grams, how
many days will it take for the substance to decay to less than 150 grams?

Answer:

m = 35

Step-by-step explanation:

2m + m -15 = 90

3m -15 = 90

     +15  +15

3m = 105

/3     /3

m = 35

To check the work just insert 35 for m:

2(35) + 35 -15 = 90

70 + 35 -15 = 90

105 - 15 = 90

90 = 90

Answer:

9) c) 1

10) c) 215

Step-by-step explanation:

Step:1

Given that the expression

      [tex]\frac{31+r}{2} - \frac{9r-5}{4}[/tex]

Put r = 9

 =    [tex]\frac{31+9}{2} - \frac{9(9)-5}{4}[/tex]

 =  [tex]\frac{40}{2} -\frac{76}{4}[/tex]

=   20 - 19

=1

Step(ii):-

Given that

[tex]\frac{5(4r-16)}{5} +13(3r-12)[/tex]

Put r = 9

=  [tex]\frac{5(4(9)-16)}{5} +13(3(9)-12)[/tex]

=  20 + 13(15)

= 215

Answer:

-12

Step-by-step explanation:

12 - 15 = -3

4 ( -3 )

= -12

Answer: -12

Step-by-step explanation:

We have 4[12 -15]

Next, we have subtract in the parentheses since it's part of PEDMAS

12-15

After that, we get -3. Whenever a you multiply a whole number with a negative number, the whole becomes negative.

12- 15= -3

And Lastly, we multiply.

4x -3= -12

Hope this helps!

Answer:

es igual a 111.111.111.011

Answer: False

Step-by-step explanation: The absolute value of -15 is 15.

Answer: (-5,1)

Step-by-step explanation: that should be right

Answer:

7/8

Step-by-step explanation:

3 1/2x1/4 Calculator!!!!!!! srry if it is not the answer.

Answer: y = 14^x

Step-by-step explanation:

Here the options are:

a y = 14^x

b y = -3*(17)^x

c y = 120x

d y = -275x

to see which function increases the fastest (or which function is steeper) we need to look at the first derivations of each one of these, and see which one is larger for every value of x:

the derivations are:

a y = x*14^(x - 1)

b y = -x*3*(17)^(x  - 1)

c y = 120

d y = -275

So we can already discard options c and d, because have constant rate of change.

Then we keep options a and b.

Always when we have an exponential function, like a^x and b^x

The one with the larger base will be steeper.

So if a > b, then:

a^x is steeper than b^x

In this case, the function:

y = -3*(17)^x

has a larger base, but, this function is negative.

This means that as x increases, our function will decrease, then this function will not "increase the fastest" (because it does not increase)

Then the left option (a: y = 14^x)

Will be the correct one.

(this will happen after some value of x, because two of the options have constant derivatives, these may be steeper for smaller values of x, and as x increases, we will see that y = 14^x is the one that increases the fastest)

Answer:

25.9

Step-by-step explanation:

If a tree casts a shadow 21 m long. Then the height of the tree will be 25.9 meters.

It's a form of a triangle with one 90-degree angle that follows Pythagoras' theorem and can be solved using the trigonometry function.

A tree casts a shadow 21 m long.

The angle of elevation of the sun is 51°.

Let h be the height of tree.

Then the height of the tree will be

tan 51° = h / 21

        h = 25.93 m

More about the right-angle triangle link is given below.

https://brainly.com/question/3770177

#SPJ2

Answer:

B

Step-by-step explanation:

B

the vertex is (-5,-2) which eliminates A and C. D says that the x intercepts are both positive which is obviously incorrect making B the correct answer

Answer:

divide 12 and 1/2 by 25 and can I get branliest

Step-by-step explanation:

Answer:

it would take him 2 minutes to read one page

He can read half a page in 1 minute

Step-by-step explanation:

Part 1

ratio time/pages

25/12.5=x/1

cross multiply

12.5x=25

x=2

ratio time/pages

25/12.5= 1/x

cross multiply

25x=12.5

x=0.5

Answer:

1) 160 2) 218.64

Step-by-step explanation:

v=lwh (length)×(width)×(height)÷3

1. 10× 6× 8= 480÷3

2. 10.6× 9.1× 6.8= 655.928 ÷ 3 =218.6426 (218.64)

Answer:

B

Step-by-step explanation:

Cross product.

3xy= 3y

4x6= 24

3y/3

24/3= 8

Answer:

A

Step-by-step explanation:

PV(1+i)^n

2000(1+.015)^x

2000(1.015)^x

A

Answer:

2. 4 meters long

Step-by-step explanation:

0. 6 times 4 equals 2. 4

Answer:

the amount of discount is $210

Step-by-step explanation:

30(.30)

90

90 is 30% of 300

subtract:

300-30= 210

Answer:$210

Step-by-step explanation:

Answer:

[tex]\frac{12}{4*5}[/tex]

Step-by-step explanation:

the quotient of 12 and the product of 4 and 5 can be written in mathematical form as:

12 / (4 * 5)   or [tex]\frac{12}{4*5}[/tex]

Answer:

n would be -4

Step-by-step explanation:

(two negatives multiplied together make a positive)

-4n = 16

/-4    /-4

n = -4

Answer:

These are the answers.

Step-by-step explanation:

Answer:

it is roughly 15.3 laps (i rounded 1.6666666666667 to 1.7) i'll explain

Step-by-step explanation:

ratio of laps to minutes: 9:12,

20/12 = 1.6666666666667 rounded to 1.7

9 x 1.7 = 15.3

sorry that i had to round and that it is a little off, hoped i helped you tho

Answer:

there are two bases and three sides/faces.

Answer:

8 1/2

2 19/36

1 9/10

23/42

Answer:  

Use continuity to evaluate the limit.

lim 16+radical x/ radical 16+x

1+9

Consider the intervals for which the numerator and the denominator are continuous.

The numerator 16+ radical x is contintuous on the interval

[0,00)

0

The denominator V16 + I is continuous and nonzero on the interval

(16,00)

X

The interval for which the quotient is continuous is the intersection of the above intervals.

16+

Therefore, the quotient

is continuous on the interval

716 +1

[-16,0]

X

Since 2

9 is in the interval (0, 0), then fis continuous at x = 9. Therefore,

19

16 + VE

lim

179 16 +2

f(9)

00

Question Help: Message instructor

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Step-by-step explanation:

Answer: 89.18

Explanation:none your welcome

Answer:

lol the answer is 49

Step-by-step explanation:

hope this helps <3

Answer:

[tex]\text{For topic A }:0.99\\\text{For Topic B}: 0.6875[/tex]

Step-by-step explanation:

Topic A: Two books are ordered

Topic B: Four books are ordered

Let X= number of books arrived

The probability that a book actually arrives in time is 0.9

i.e., p=0.9

For Topic A:

[tex]P(X\geq 1)=P(X=1)+P(X=2)\\\Rightarrow P(X\geq 1)= \;^2C_1 (0.9)^1(0.1)^(2-1)+\;^2C_2 (0.9)^2(0.1)^(2-2)\\\Rightarrow P(X\geq 1)=0.18+0.81\\\Rightarrow P(X\geq 1)=0.99[/tex]

For Topic B:

[tex]P(X\geq 2)=P(X=2)+P(X=3)+P(X=4)\\\Rightarrow P(X\geq 2)=1-[P(X=0)+P(X=1)]\\\Rightarrow P(X\geq 2)=1-[\;^4C_0(0.5)^0(0.5)^4 +\;^4C_0(0.5)^1(0.5)^3]\\\Rightarrow P(X\geq 2)=1-[0.0625+0.25]\\\Rightarrow P(X\geq 2)=0.6875[/tex]

Answer:

48

Step-by-step explanation:

4x2=8

4x3=12

12/2=6