Question

Solve for x.

x2 + 4x - 21 = 0
A.
-3, -7
B.
-3, 7
C.
3, -7
D.
3, 7

Answer 1

Step-by-step explanation:

I have solved the question in the photo.

Hope it helps

Answer 2

Answer:

option C

Step-by-step explanation:

${x}^{2} + 4x - 21 = 0 \\{x}^{2} + 7x - 3x - 21 = 0 \\ x(x + 7) - 3(x + 7) = 0 \\ (x - 3)(x + 7) = 0$

either,

x-3=0 x+7=0

x=3 x=-7