Solve for x.

9x+9x-21=33
(1 point)
A. x=6
B. x=3
C. x=8
D. x=1

To solve for x in the equation 9x + 9x - 21 = 33, we need to combine like terms and isolate the variable.

First, combine the terms on the left side of the equation:
18x - 21 = 33

Next, add 21 to both sides of the equation to eliminate the constant term on the left side:
18x - 21 + 21 = 33 + 21
18x = 54

Finally, divide both sides of the equation by 18 to solve for x:
18x/18 = 54/18
x = 3

Therefore, the correct answer is B. x = 3.