How do you solve –4 sqrt(x+2) + 3 = -9?

1 Answer
Jun 20, 2016

x=7

Explanation:

First, isolate the term including x using subtraction.

-4sqrt(x+2)+3 = -9

=>-4sqrt(x+2)+3-3 = -9 - 3

=> -4sqrt(x+2) = -12

Next, change the coefficient of sqrt(x+2) to 1 using division.

=> (-4sqrt(x+2))/(-4) = (-12)/(-4)

=> sqrt(x+2) = 3

Next, eliminate the square root by squaring each side.

=>(sqrt(x+2))^2 = 3^2

=> x+2 = 9

Finally, isolate x using subtraction.

=> x+2-2 = 9-2

=>x = 7

And, as good practice, check your answer:

-4sqrt(7+2)+3 = -4sqrt(9)+3

=-4(3)+3

=-12+3

=-9

as desired.