Question 146707
Simplify each:
x^2 – 7x + 12
Factors of a*c or (12) that sum to b or (-7) ? Yes: -4, -3
x^2 – 4x - 3x + 12
(x^2 – 4x) + (-3x + 12)
x(x – 4) - 3(x - 4)
(x - 3)(x - 4)
Now:
x^2 – 16 is in the form (x^2 - a^2) = (x - a)(x + a)
x = x and a = 4
(x - 4)(x + 4)
So that:
[ (x - 3)(x - 4) ] / [ (x - 4)(x + 4) ]
(x - 3) / (x + 4) Is your answer!