Solution

153650

Problem / game
Factorisable Quadratics Back to problem
First name
Riya
School
St Stephens School Carramar
Country
Australia
Age
15

1d. If the quadratic x^2+bx-16 factorises as (x+c)(x+d), then c & d must multiply to give -16. Therefore c & d must be factors of -16.

The pairs of factors that multiply -16: (4,-4), (-8,2), (-2, 8), (-1,16), (-16,1)

Therefore the possible brackets that expand out to x^2+bx-16 are:
(x+4)(x-4)
(x-8)(x+2)
(x-2)(x+8)
(x-1)(x+16)
(x-16)(x+1)