SOLUTION: Solve √ (3x+4) + x = 12 Can you please help me out? Thanks so much in advance :)

Algebra ->  Square-cubic-other-roots -> SOLUTION: Solve √ (3x+4) + x = 12 Can you please help me out? Thanks so much in advance :)       Log On


   

Question 807912: Solve
√ (3x+4) + x = 12
Can you please help me out? Thanks so much in advance :)
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

sqrt%283x%2B4%29+%2B+x++=+12......move x to the right

sqrt%283x%2B4%29++=+12-x...square both sides


%28sqrt%283x%2B4%29%29%5E2++=+%2812-x%29%5E2
3x%2B4++=+12%5E2-24x%2Bx%5E2
0=+144-24x-3x-4%2Bx%5E2
x%5E2-27x%2B140=0.......factor completely, write -27x as -20x-7x
x%5E2-20x-7x%2B140=0....group
%28x%5E2-20x%29-%287x-140%29=0
x%28x-20%29-7%28x-20%29=0
%28x-7%29%28x-20%29=0
solutions:
if %28x-7%29=0=> x=7
if %28x-20%29=0=> x=20