
Andy C. answered 05/03/18
Tutor
4.9
(27)
Math/Physics Tutor
sqrt(x+7) + 2 = sqrt(3-x)
(x+7) + 2*2*sqrt(x+7) + 4 = 3-x
x+11 + 4*Sqrt(x+7) = 3-x
4*sqrt(x+7) = 3 - x - x - 11
4*Sqrt(x+7) = -2x - 8
sqrt(x+7) = (-1/2)(x+4)
x+7 = (1/4)(x+4)^2
(1/4)(x^2+8x+16) - x - 7 = 0
x^2 + 8x + 16 - 4x - 28 = 0
x^2 + 4x - 12 = 0
( x + 6)( x - 2 ) = 0
x=-6 or x = 2
CHECK:
X=-6:
sqrt(-6+7)+2 = sqrt(1) + 2 = 1+2= 3 vs. sqrt(3 - -6) = sqrt( 9) = 3
X=2:
sqrt(2+7) = sqrt(9) = 3 vs. sqrt(3-2) = sqrt(1) = 1
The only solution is x=-6