solve fx5x348x280x40Solutionfx5x348x280x40 fx 5x3 2x2 50x2

solve: f(x)=5x^3-48x^2+80x+40

Solution

f(x)=5x^3-48x^2+80x+40

f(x) = 5x^3 + 2x^2 -50x^2 - 20x +100x + 40

f(x) = x^2 ( 5x+2) - 10x(5x+2) + 20 (5x+2)

f(x) = (5x+2) (x^2 - 10x + 20)

so

solution is

5x+2 = 0

so x= -2/5

or x^2 -10x + 20 = 0

so x = 7.23 or x=2.7639