7x^2132=0 iff
(7x + 1)(x  2) = 0 iff
x = 1/7 or x = 2
(7x + 1)(x  2) = 0 iff
x = 1/7 or x = 2

Supposing you meant:
7x^213x2=0
Factor:
(x  2) (7x + 1) = 0
Use the zero product principle twice:
x = 2, 1/7
7x^213x2=0
Factor:
(x  2) (7x + 1) = 0
Use the zero product principle twice:
x = 2, 1/7

use the quadratic formula

I assume you mean: 7x^213x2
(7x  1) (x + 2)
(7x  1) (x + 2)