Question 307796
56x^3 + 98x= 170x^2

56x^3 + 98x- 170x^2=0

2x(28x^2-85x+49)=0
(28x^2-85x+49)=0

using the quadratic equation

a=28, b= -85 , c = 49

The roots x1,x2 = -b +/- sqrt(b^2-4ac)  /2a

x1= +85 + sqrt{( -85)^2 - 4*28*49}/2*28
x1= 2.26
.

x2=+85 -sqrt{( -85)^2 - 4*28*49}/2*28
x2= 0.77