Answer:
C. Divide both sides of the equation by -2.
Step-by-step explanation:
The goal of the equation is to isolate x. In order to do that we have to remove the '-2' by doing the inverse operation. That is the opposite operation, for example addition and subtraction, multiplication and division.
Since x is being multiplied by -2, we do the inverse which is division.
Answer:

Step-by-step explanation:
Percentage means "out of hundred" So measuring the rate in percentage we've to find it using "per 100 units".
Answer:
The tank is 10cm high
Step-by-step explanation:
Given
-- length
-- width
--- water lever

Required
The height of the tank
Let y represents the remaining fraction before water is added.
So:

Make y the subject


Solve


Represent the volume of the tank with v
So:

Make v the subject

Substitute: 


Represent the height of the tank with h;
So, the volume of the tank is:

Make h the subject

Substitute values for v, l and w

Convert 30L to cm^3


