+8581 solve the following use the quadratic formula,
1x^2 + 12x = 64
I've tried to do this several times, but for some reason, I cannot do it . :(
(Proomise this is my last question for today..!!)
:)
Solve for x over the real numbers:
x^2+12 x = 64
Subtract 64 from both sides:
x^2+12 x-64 = 0
x = (-12±sqrt(12^2-4 (-64)))/2 = (-12±sqrt(144+256))/2 = (-12±sqrt(400))/2:
x = (-12+sqrt(400))/2 or x = (-12-sqrt(400))/2
sqrt(400) = sqrt(16×25) = sqrt(2^4×5^2) = 4×5 = 20:
x = (-12+20)/2 or x = (-12-20)/2
(-12+20)/2 = 8/2 = 4:
x = 4 or x = (-12-20)/2
(-12-20)/2 = -32/2 = -16:
Answer: | x = 4 or x = -16
