The quadratic expression (𝑥+4)(𝑥−10) ( x + 4 ) ( x − 10 ) is written in factored form.

Question

The quadratic expression (𝑥+4)(𝑥−10)(x+4)(x−10) is written in factored form.

Write the expression in general form 𝑎𝑥2+𝑏𝑥+𝑐ax2+bx+c.

Write the expression in vertex form 𝑎(𝑥−ℎ)2+𝑘a(x−h)2+k.

Answer 1

(x+4)(x-10) use FOIL

= x^2 -6x -40 where a=1, b =-6, c =40

complete the square, add and subtract 9,

=(x^2 -6x + 9) -40 -9

= (x-3)^2 -49 vertex is (3, -49)