Question

Let x^2+2x-15 =0 use quadratic formula to find the roots. (roots are whole numbers)

Answer 1

Hello!

We have:

X^2 + 2x-15 = 0

Where:

a = 1
b = 2
c = -15

Delta = b^2 -4.a.c

D = 2^2 - 4.1.(-15)

D = 4 + 60

D = 64

We know,

x = [ -b+/-Raiz(delta)]/2a

x = [ -2 +/- Raiz(64)]/2

x = [-2 +/- 8]/2

Then,

x' = (-2-8)/2 <=> -5

And

x" = (-2+8)/2 <=> 3