Answer:

Step-by-step explanation:
Given 
Let 
Interchange x and y

Solve for y, by first squaring both sides


Hence

The last choice is correct
Answer:
Amount of paint to be bought = 10 gallons
Step-by-step explanation:
Amount of paint needed by Mrs. Sullivan to paint her house = 12 gallons
She is already having paint = 8 quarts
Since, 1 quart = 0.25 gallons
Therefore, 8 quarts = 8 × 0.25
= 2 gallons
So, amount of paint she is already having = 2 gallons
Amount of paint to be bought = 12 - 2
= 10 gallons
Answer:
Joe is 14.
Martha is 28.
Step-by-step explanation:
Use the variables and information from the question to make equations.
If Joe's age is half Martha's:
(1/2)m = j OR 2j = m
If their ages combined is 42:
m + j = 42
We can substitute the equation m=2j into equation m + j = 42, replacing "m".
m + j = 42 Substitute m for 2j
2j + j = 42 Combine like terms, terms with same varables
3j = 42 Divide both sides by 3 to isolate j
j = 14 Joe's age
Since j = 14, we can substitute it into equation m=2j to find "m".
m = 2j Substitute j for 14
m = 2(14) Simplify
m = 28 Martha's age
Therefore Joe is 14 and Martha is 28.
Daddy remember when you made my butt sore