Question 992036

I am not having good luck with this answer. Please help!!!

{{{2x-3=sqrt(30-7x)}}} 

I squared off the expression 2x-3 and used the FOIL method to get this:

4x-12x+9=30-7x I continue by subtracting 4x-12x to get -8x+9=30-7x. Here's where I think I lose it. 
Somewhere I'm missing something because I keep getting x=21 but the answer key says {3} 
<pre>First error: {{{(2x - 3)^2 = 4x^2 - 12x + 9}}}, not: {{{4x - 12x + 9}}}. Major error!!