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2 years ago

Justify each step. 15. 2x – 5 = –20 2x = -15 x=_15

Mathematics

1 answer:

Dimas [21]2 years ago

5 0

1st: add 5 to each side
2nd: divide by 2 on each side

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Help!! Which number is NOT in scientific notation?

ki77a [65]

D is not in correct scientific notation. To be correct, the answer would be 5.0 x 10^2

If this helped you, please list me as brainliest!

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3 years ago

The sum of three numbers is 69. If the second number is equal to the first diminished by 8, and the third number is 5 times the

bonufazy [111]

X = first number
x - 8 = 2nd number
5x = 3rd number

x + x - 8 + 5x = 69
7x - 8 = 69 <=== this is the equation u would use

7x - 8 = 69
7x = 69 + 8
7x = 77
x = 11

1st number = 11
2nd number : x - 8 = 11 - 8 = 3
3rd number : 5x = 5(11) = 55

3 0

2 years ago

Read 2 more answers

Hi can someone plz help me with #1...it’s being graded. sos thanks so much!!

densk [106]

1:105::25:X
105*25whole divided by 1*X
2625

3 0

3 years ago

Read 2 more answers

Find the total number of unit cube that fill the entire prism

Nonamiya [84]

Answer:

72 cubes

Step-by-step explanation:

Attached is the picture drawn (though not great one), showing 6 cube on length of prism, 3 cubes on width and 4 cubes on height of prism.

Given: Length of prism= 6

Width= 3

Height= 4

To know the number of cubes, which can fill the entire prism, we need to find volume of prism.

∴ Volume of prism= $length\times width\times height$

Volume of prism= $6\times 3\times 4= 72$

∴ 72 units of cube can fill the entire prism.

3 0

2 years ago

Radioactive Waste The rate at which radioactive waste is entering the atmosphere at time t is decreasing and is given by Pe^-kt,

Dmitry_Shevchenko [17]

Answer:

$\displaystyle{\int^{\infty}_0 {50e^{-0.04t}}\, dt}=1250$

Step-by-step explanation:

Given:

$T =\displaystyle{\int^{\infty}_0 {Pe^{-kt}} \, dt}$

where,

T = total amount of waste

P = 50, the initial rate

k = 0.04

t = time

$T =\displaystyle{\int^{\infty}_0 {50e^{-0.04t}} \, dt}$

now we need to solve this integral!

$T =\displaystyle{50\int^{\infty}_0 {e^{-0.04t}} \, dt}$

$T = \left|50\left(\dfrac{e^{-0.04t}}{-0.04}\right)\right|^{\infty}_0$

$T = \left|-1250e^{-0.04t}\right|^{\infty}_0$

$T = (-1250e^{-0.04(\infty)})-(-1250e^{-0.04(0)})$

when any number has a power of negative infinity it is 0. because: $a^-{\infty} = \dfrac{1}{a^{\infty}} = \dfrac{1}{\infty} = 0$ , like something being divided by a very large number!

$T = (-1250(0))-(-1250e^0)$

$T = 1250$

this is the total amount of waste

6 0

2 years ago