3*x - 10 + -8*x + 5 = 10
(3*x-10)-(8*x-5) = 10
3*x-10-8*x+5 = 10
-5 - 5*x = 10
x = 15 / (-5)
sum
-3
=
product
x1 = -3
x1 = -3.0