Question
can you show me step by step how to factor 15x^2-14x-8
Answers
Reiny
I don't know what method you are learning.
One of the popular methods these days seems to be
the "decomposition" method
multiply first times last: 15(-8) = -120
look for factors of -120 which add up to -14
how about +6 and -20 ?
their sum is -14
so 15x^2 - 20x + 6x - 8
= 5x(3x-4) + 2(3x-4)
= (3x-4)(5x+2)
One of the popular methods these days seems to be
the "decomposition" method
multiply first times last: 15(-8) = -120
look for factors of -120 which add up to -14
how about +6 and -20 ?
their sum is -14
so 15x^2 - 20x + 6x - 8
= 5x(3x-4) + 2(3x-4)
= (3x-4)(5x+2)