Question

Write a quadratic equation in standard form (with integer coefficients) that has roots: 2 and -5?

Answer 1

y = x^2 +3x-10

Explanation:

If we know the roots of a quadratic function, we know that

y = (x -a) (x-b) where a and b are the roots

y = (x-2 ) (x--5)

y = (x-2)(x+5)

We need to foil this out to get this in standard form of ax^2 + bx+c

FOIL (x-2) (x+5)

First x*x: x^2

outer : 5*x = 5x

inner: -2x = -2x

last : -2*5 = -10

Add them up

x^2 +5x-2x-10

x^2 +3x-10