Answer:
12 inches
Step-by-step explanation:
let length be L
formula for perimeter of rectangle = 2( length + width )
2( L + 9) = 42
2L + 18 = 42
2L = 24
L = 12 inches
I would say C instead of A but I am not so sure.
Answer: n = 6 or you can do n = -6
Step-by-step explanation:
solve for n and then the left hand side factors
into a product with for terms then multiply both sides by -2 then split into two equations after add 6 to both sides and subtract 6 from both sides.