How do you factor by grouping t^3+2t^2-7t-14t3+2t27t14?

1 Answer
May 10, 2015

t^3 + 2t^2 - 7t - 14 = (t^3 + 2t^2) - (7t + 14)t3+2t27t14=(t3+2t2)(7t+14)
= t^2(t + 2) - 7(t + 2) = (t^2 - 7)(t + 2)=t2(t+2)7(t+2)=(t27)(t+2)

So grouping the first two terms together and the last two terms together allows us to notice the common factor (t + 2)(t+2).

If we allow irrational coefficients, (t^2 - 7)(t27) factors as (t - sqrt(7))(t + sqrt(7))(t7)(t+7).