Question

Need the answer, i want to make sure its right.

Answer 1

A=LW
W=7+(1/2)L
A=156
L(7+(1/2)L)=156
7L+(1/2)L^2=156
times both sides by 2
L^2+14L=312
minus 312 both sides
L^2+14L-312=0
what 2 numbers multiply to get -312 and add to get 14?
-12 and 26
(L-12)(L+26)=0
set to zero
L-12=0
L=12

L+26=0
L=-26, false, can't have negative measure

L=12
W=7+(1/2)L
W=7+(1/2)(12)
W=7+6
W=13

length=12m
width=13m

Answer 2

I think the width is 13 and the length is 12