Question 978100
(2x-3)(x+9)= 2x^2+15x-27

2 times that is 4x^2+30x-54
but x=4x^2-30x-54]  ;; original equation was x=2y+5
subtract x from both sides
0=4x^2+29x-49
You are right about the 5.  That has to be carried through.