How can i solve this by factoring?

Question

5x^2 +8x - 69=0

x=?

Answer 1

5 is a prime number, thus its factors are 5 and 1. Factors of 69 are 23 and 3.It helps to factor the expressions in the following way:

                     5x² +8x - 69 = (5x +23)(x-3).   

If you make it equal zero then you will obtain:  5x +23 = 0    and x-3 = 0.

Thus your solutions are x = -23/5    and x = 3.