How do you factor #-x^2 + x + 42#?

2 Answers
Jul 4, 2017

See a solution process below:

Explanation:

By playing with the factors of #42# (1, 2, 3, 6, 7, 14, 21, 42) and #-1# (1, -1) This can be factored as:

#(-x + 7)(x + 6)#

Jul 4, 2017

f(x) = - (x + 6)(x - 7)

Explanation:

#f(x) = - x^2 + x + 42 = - (x^2 - x - 42)#
Find 2 numbers knowing sum (b = - 1) and product (c = - 42).
They are: 6 and -7.
Factored form:
#f(x) = - (x + 6)(x - 7)#