Question

For what values of x does the following hold true: (4x+7)^2=(7x+4)^2

Answer 1

x=1,x=-1

Explanation:

(4x+7)^2=(7x+4)^2

16x^2+56x+90=49x^2+56x+16

16x^2+56x+49-49=49x^2+56x+16-49

16x^2+56x=49x^2+56x-33

16x^2+56x-56x=49x^2+56x-33-56x

16x^2=49x^2-33

16x^2-49x^2=49x^2-33-49x^2

-33x^2=-33

x^2=1

x=1,-1