Question

Fan and Medal

Find the roots of the polynomial equation.



x^2 – x – 72 = 0









A.

9 and –8








B.

–6 and 6








C.

–2 and 16








D.

–9 and 8

Answer 1

@ranga

Answer 2

x^2 – x – 72 = 0
Factor the left hand side:
x^2 - 9x + 8x - 72 = 0
Can you factor now?

Answer 3

x+8(x-9) is what I got @ranga

Answer 4

Yes. (x+8)(x-9) = 0
Therefore, x + 8 = 0 or x - 9 = 0
x = -8 or x = 9. Those are the roots of the polynomial because those x values makes the polynomial zero.