Step-by-step explanation:
Well in general, we can represent subtraction as: 
"z" represents the difference, and it really just represents x with y taken away. So if we were to "give back" this y value, we should get "x".
This means that: 
So one way to check, is adding the value that's being subtracted (y value) and the difference (z value), this should get you the value that is being subtracted from (x value). If you don't get the original value that's being subtracted from (x-value) then you know the answer you got is wrong.
Answer:
C. 36+12m
Step-by-step explanation:
When you distribute a number outside the parenthesis, you multiply it to all numbers nor letters in the parenthesis. Hopes this helps
Answer:
It is 20
Step-by-step explanation:
Use your fingers if necessary
Answer is A. 406m2 so there is the answer to anyone who comes across this.