Question

Find all roots and check your answer

5x^3-23x=57x

Answer 1

5x^3 - 23x - 57x = 0
5x^3 - 80x = 0
x(5x^2 - 80) = 0
so x = 0 is one solution

5x^2 - 80 = 0
x^2 - 16 = 0
x = sqrt(16)
so x = -4, +4 is two other solutions

Answer 2

can i ask you another one

Answer 3

ok

Answer 4

2(x+15)=9x+2(x^2-15)

Answer 5

2x + 30 = 2x^2 - 30 + 9x
moving to the right
2x^2 + 7x - 60 = 0
(2x + 15)(x - 4)

Answer 6

so the roots are 2x+15 and x-4

Answer 7

2x + 15 = 0 so one root is x = -15/2
x -4 = 0 so other root is x=4

Answer 8

oh ok thank you