i need help with my math homework?

Question

can anyone help me solve this problem?
x=the square root of x+13+7
a)12
b)3
c)3,12
d)-9
tell me how you got if you can

THANKS EVERYONE WHO WAS TRYING TO SERIOUSLY HELP ME.
i couldn't find a square root key on my computer thats why i wrote it like that.
any way imagine this is one of those radical signs \ and the problem looks like this x=\x+13+7)

Answer 1

you need parentheses.

is it x = sqrt(x+13+7) or:

x = sqr(x) + 13 + 7 or:

x = sqr(x+13) + 7 ?
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well, i still can't figure out the equation so i am gonna solve all three.

x = sqr(x + 20)
x^2 = x + 20
x^2 - x - 20
(x-5)(x+4)
x = -4 or 5

so this is not the equation.
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x = sqr(x+13) + 7
x - 7 = sqr(x+13)
x^2 - 14x + 49 = x + 13
x^2 - 15x + 36
(x -12) (x-3)
x = 12 or 3

well, i guess this is the equation.

but you have to check
3 = sqr(3 + 13) + 7
3 = 4 + 7
3 is not equatl to 11 so it is not the answer

12 = sqr(12+13) + 7
12 = sqr(25) + 7
12 = 5 + 7
12 = 12

so the final answer is 12 or A

Answer 2

x = root of x + 13 + 7
Let |x be square root of x.
x = |x + 13 + 7
x = |x + 20
x/( |x) = 20
|x = 20
x = 400
Seems like there is problem in the question.

Answer 3

Based on the equation that SOMEBODY proposed I say that it's c)3,12.