Question

$x^{2} - 21x + 80$factoring I need help

Answer 1

x^2 - 21x + 80

Find

A x B = 80

A+B=- 21

Then 80 = 16•5. or also (-16)•(-5)

A+ B= -16 - 5 = -21

Then write, answer is

x^2 - 21x + 80 = ( x - 16)•(x - 5)

Answer is

( x - 16)•(x - 5)