8p² - 16p = 10
8p² - 16p - 10 = 0 Divide through by 2
4p² - 8p - 5 = 0
Multiply first and last coefficients: 4*-5 = -20
We look for two numbers that multiply to give -20, and add to give -8
Those two numbers are 2 and -10.
Check: 2*-10 = -20 2 + -10 = -8
We replace the middle term of -8p in the quadratic expression with 2p -10p
4p² - 8p - 5 = 0
4p² + 2p - 10p - 5 = 0
2p(2p + 1) - 5(2p + 1) = 0
(2p + 1)(2p - 5) = 0
2p + 1 = 0 or 2p + 5 = 0
2p = 0 -1 2p = 0 - 5
2p = -1 2p = -5
p = -1/2 p = -5/2
The solutions are p = -1/2 or -5/2
