Answer:
x = - 4 , x = 1
Explanation:
given the equation
x² + 3x - 4 = 0
consider the factors of the constant term (- 4) which sum to give the coefficient of the x- term (+ 3)
the factors are + 4 and - 1 , since
+ 4 × - 1 = - 4 and + 4 - 1 = + 3
use these factors to split the x- term
x² + 4x - x - 4 = 0 ( factor the first/second and third/fourth terms )
x(x + 4) - 1(x + 4) = 0 ← factor out (x + 4) from each term
(x + 4)(x - 1) = 0
equate each factor to zero and solve for x
x + 4 = 0 ⇒ x = - 4
x - 1 = 0 ⇒ x = 1