Question

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

Answer 1

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)`

Answer 2

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)`