Answer:
x = - 1 , x = -
Explanation:
given
7x² + 2 = - 9x ( add 9x to both sides )
7x² + 9x + 2 = 0 ← quadratic equation in standard form
consider the factors of the product of the coefficient of the x² term and the constant term which sum to give the coefficient of the x- term.
product = 7 × 2 = 14 and sum = + 9
the factors are + 7 and + 2
use these factors to split the x- term
7x² + 7x + 2x + 2 = 0 ( factor the first/second and third/fourth terms )
7x(x + 1) + 2(x + 1) = 0 ← factor out (x + 1) from each term
(x + 1)(7x + 2) = 0 ← in factored form
equate each factor to zero and solve for x
x + 1 = 0 ( subtract 1 from both sides )
x = - 1
--------------
7x + 2 = 0 ( subtract 2 from each side )
7x = - 2 ( divide both sides by 7 )
x = -