Question 1015587
2(L+W)=50

L=2W-5

Take the value of L from eq 2 and substitute into eq 1

2((2W-5)+W)=50

(2W-5)+W=25

3W-5=25

3W=30

W=10

L=(2*10)-5 = 15

W=10 L=15

Check work  

Perimeter = 2(L+W) = 2(15+10)= 50 (yes)

Length (15) is 5 less than twice width (15)  ((2*10)-5) = 10 (yes)