x/8+x/10=9/8 solve for x
x/8+x/10=9/8 multiply through by the common denominator of 8 and 10 = 40
40(x/8) + 40(x/10) = 40(9/8)
5x + 4x = 45 sinplify
9x = 45 divide both sides by 9
x = 5