For question one.
Substitute numbers for variable
7=m*5+10
fip equation
5m +10=7
now solve for m
subtract 10 from both sides
5m=-3
divide both sides by 5
you end up with a fraction
Answer -3/5
Question 2
perimeter of a rectangle is p=2L+2W
L=length W=width
They are telling you that L=12 and W=5
substitute numbers for variables
p=2*12+2*5
Answer 35
