Answer:
Equivalent expressions are expressions which are equal. This means they simplify to the same expression. Simplify the two expressions -1.3x - (-8.9x) = 7.6x and -1.3 + (-8.9X) = -10.2x.
Then simplify each option to determine if it is equal -1.3x - (-8.9x), -1.3 + (-8.9X) or neither:
−1.3x−8.9x = -10.2x. This is equivalent to -1.3 + (-8.9X) .
8.9x+(−1.3x) = 7.6x This is equivalent to -1.3x - (-8.9x) .
−8.9x+(−1.3x) = -10.2x This is equivalent to -1.3 + (-8.9X) .
8.9x−(−1.3x) = 10.2x Neither
−1.3x+8.9x = 7.6x This is equivalent to -1.3x - (-8.9x) .
−8.9x+1.3x = -7.6x Neither
Step-by-step explanation:
Since a and 5 aren't like terms, you would write the expression as 
X = -3
Pull out the like terms: -7x - 21 = -7 × ( x + 3)
Solve: -7 = 0
Solve: x + 3 = 0
Subtract 3 from both sides of the equation
So, x = -3
-First we have to work out what’s in parenthesis.
(8*10^-3)=(8*0.001)=0.008
-This is for the second parenthesis
(2*10^-4)=(2*0.0001)=0.0002
-Now we multiply them together
ANSWER: 0.0000016
Step-by-step explanation:
The volume of a cube is

where a is the side length,
Note: If you want to remember this formula, know that a cube is basically a bunch of squares stacked on one another vertically and horizontally
The area of a square with side length a, is

If we multiply that by the height of the cube, which is a.

That is the easy way to derive the formula of the volume of a cube.
Back on track, we know the volume so we must solve for a.
1.

Assuming you took algebra, to isolate the variable a, we must undo it being raised to the third power.
To do this, we take the cube root of both sides
![\sqrt[3]{125} = \sqrt[3]{a {}^{3} }](https://tex.z-dn.net/?f=%20%5Csqrt%5B3%5D%7B125%7D%20%20%3D%20%20%5Csqrt%5B3%5D%7Ba%20%7B%7D%5E%7B3%7D%20%7D%20)
The cube root of 125 is 5 so

5 cm
2.

![\sqrt[3]{8} = \sqrt[3]{ {a}^{3} }](https://tex.z-dn.net/?f=%20%5Csqrt%5B3%5D%7B8%7D%20%20%3D%20%20%5Csqrt%5B3%5D%7B%20%7Ba%7D%5E%7B3%7D%20%7D%20)

2 ft
3.


7 yd
4.


10 mm
5.


12 in. or 1 ft
6.


1 m