How do you solve x2 plus 7x plus 12 using quadratic formula?

Answer 1

If: x2+7x+12 = 0

Then: (x+4)(x+3) = 0

So it follows: x = -4 and x = -3

* * * * *

True, but that is not using the quadratic formula.

According to the quadratic formula, for the equation ax2 + bx + c = 0:

x = [-b ± sqrt(b2 - 4*a*c)]/(2*a)

= [-7 ± sqrt(72 - 4*1*12)]/(2*1)

= [-7 ± sqrt(49 - 48)]/2

= [-7 ± sqrt(1)]/2

= [-7 ± 1]/2

= [-7 -1]/2 or [-7 +1]/2

=-8/2 or -6/2

= -4 or -3