Question 12902
let x.x  = y & this shall become a quad eqn in y viz
9y.y = 25y - 16
9y.y -16y -9y+16 = 0
(9y-16)(y-1) = 0
y= 16/9 or y = 1
Subs x.x for y
x.x = 16/9 or x.x = 1
taking square root we get x = 4/3 or x = 1