x(x)+(3x)(3x)=490

Solution for x(x)+(3x)(3x)=490 equation:

Simplifying
x(x) + (3x)(3x) = 490

Multiply x * x
x2 + (3x)(3x) = 490

Remove parenthesis around (3x)
x2 + 3x(3x) = 490

Remove parenthesis around (3x)
x2 + 3x * 3x = 490

Reorder the terms for easier multiplication:
x2 + 3 * 3x * x = 490

Multiply 3 * 3
x2 + 9x * x = 490

Multiply x * x
x2 + 9x2 = 490

Combine like terms: x2 + 9x2 = 10x2
10x2 = 490

Solving
10x2 = 490

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Divide each side by '10'.
x2 = 49

Simplifying
x2 = 49

Take the square root of each side:
x = {-7, 7}