Answer
My answer is in the photo above
90= 3x + 2x
90= 5x
x= 18
one measure = 3(18)= 54
the other one= 2(18)= 36
hope this helps!
Factoring f(x) would give a factor (x-1-2i), so you can divide f(x) by this, leaving (x-3)(x+4)(x-1+2i), so the other roots are:
x=3
x=-4
x=1-2i