Question

Which of the following are the solutions of the equation 2x^2+2x=4-x

(A) x=4 and x=1
(B) x=4 and x= -1/2
(C) x= 3+√35/4 and x=3-√35/4
(D) x=-3+√41/4 and -3-√41/4
(E) -3+i√23/2 and -3-i√23/2

Answer 1

2x² + 2x = 4 - x
+ x + x
2x² + 3x = 4
2x² + 3x - 4 = 0
x = -(3) +/- √((3)² - 4(2)(-4))
2(2)
x = -3 +/- √(9 + 32)
4
x = -3 +/- √(41)
4
x = -3 +/- 6.4
4
x = -0.75 + 1.6
x = -0.75 + 1.6 x = -0.75 - 1.6
x = 0.85 x = -16.75

The answer is equal to D. x = -0.75 + √(41)/4 and x = -0.75 - √(41)/4.