Question 1126704
When you substitute, you get

5u^2+7u+2=8

5u^2+7u-6=0

(5u-3)(u+2)=0

5u-3=0

5u=3

u=3/5

5/x=3/5

3x=25

x= 25/3

AND

u=-2

5/x = -2

x=-5/2