Identify the solutions to the quadratic equation

x2 + 4x-21 = 0
Check all that apply
O A. x= 3
B. X= -7
O C. x = 21
O D. x= -5
O E. x= 4

A.x=3

B.x=-7

Step-by-step explanation:

Hi, to answer this question we have to apply the quadratic formula:

For: ax2+ bx + c

x =[ -b ± √b²-4ac] /2a

Replacing with the values given:

x =[ -4 ± √(4)²-4(1)-21] /2(1)

x = [-4 ± √16 +84] /2

x = [ -4 ± √100] /2

x = [ -4 ± 10] /2

Positive:

x = [-4 + 10] /2 = 6 /2 = 3

Negative:

x = [ -4 - 10] /2 = -14/2 = -7

So, the solutions are :

A.x=3

B.x=-7

Feel free to ask for more if needed or if you did not understand something.

-4,2,4

Step-by-step explanation: