Solve and Check.
2007-12-19 14:44:54 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
x^2+4x=-18
factor x
= x(x+4)=-18
x=-18 ; x+4=0(x=-4) ans
2007-12-19 14:52:05 · answer #1 · answered by j36 1 · 1⤊ 0⤋
X^2+4x=-18
X^2+4x+18=0
(x+6)(x-3)=0
2007-12-19 14:58:14 · answer #2 · answered by Robert S 7 · 0⤊ 0⤋
Solved by completing the square:
x^2 + 4x = -18
x^2 + 4x + ___ = -18 + ____
divide 4 by 2 = 2 , square (2) = 4
now substitute..
x^2 + 4x + 4 = -18 + 4
*** (x+2)^2 is the same as x^2 + 4x + 4 ***
(x+2)^2 = -18 + 4
(x+2)^2 = -14
now take square root of both sides.
(x+2) = +- i square root of 14
So, x = -2 +- i square root of 14
2007-12-19 15:02:22 · answer #3 · answered by hello 3 · 0⤊ 0⤋
shouldn't you be doing this???
you have to use the quadratic equation, and I really don't feel like doing it, or typing it out.
2007-12-19 14:48:24 · answer #4 · answered by jilliane421 2 · 0⤊ 1⤋