Question 443579
(B) 
x(5x+1)=18
5x^2+x-18=0 
5*-18=-90; 10 and -9 are the two factors of -90 whose sum is 1.
5x^2+10x-9x-18=0
5x(x+2)-9(x+2)=0
(5x-9)(x+2)=0
x=-2, x=9/5
.
Ed