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3\left(x+5\right)^{2}\times 3=3
Multiply x+5 and x+5 to get \left(x+5\right)^{2}.
3\left(x^{2}+10x+25\right)\times 3=3
Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(x+5\right)^{2}.
9\left(x^{2}+10x+25\right)=3
Multiply 3 and 3 to get 9.
9x^{2}+90x+225=3
Use the distributive property to multiply 9 by x^{2}+10x+25.
9x^{2}+90x+225-3=0
Subtract 3 from both sides.
9x^{2}+90x+222=0
Subtract 3 from 225 to get 222.
x=\frac{-90±\sqrt{90^{2}-4\times 9\times 222}}{2\times 9}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 9 for a, 90 for b, and 222 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-90±\sqrt{8100-4\times 9\times 222}}{2\times 9}
Square 90.
x=\frac{-90±\sqrt{8100-36\times 222}}{2\times 9}
Multiply -4 times 9.
x=\frac{-90±\sqrt{8100-7992}}{2\times 9}
Multiply -36 times 222.
x=\frac{-90±\sqrt{108}}{2\times 9}
Add 8100 to -7992.
x=\frac{-90±6\sqrt{3}}{2\times 9}
Take the square root of 108.
x=\frac{-90±6\sqrt{3}}{18}
Multiply 2 times 9.
x=\frac{6\sqrt{3}-90}{18}
Now solve the equation x=\frac{-90±6\sqrt{3}}{18} when ± is plus. Add -90 to 6\sqrt{3}.
x=\frac{\sqrt{3}}{3}-5
Divide -90+6\sqrt{3} by 18.
x=\frac{-6\sqrt{3}-90}{18}
Now solve the equation x=\frac{-90±6\sqrt{3}}{18} when ± is minus. Subtract 6\sqrt{3} from -90.
x=-\frac{\sqrt{3}}{3}-5
Divide -90-6\sqrt{3} by 18.
x=\frac{\sqrt{3}}{3}-5 x=-\frac{\sqrt{3}}{3}-5
The equation is now solved.
3\left(x+5\right)^{2}\times 3=3
Multiply x+5 and x+5 to get \left(x+5\right)^{2}.
3\left(x^{2}+10x+25\right)\times 3=3
Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(x+5\right)^{2}.
9\left(x^{2}+10x+25\right)=3
Multiply 3 and 3 to get 9.
9x^{2}+90x+225=3
Use the distributive property to multiply 9 by x^{2}+10x+25.
9x^{2}+90x=3-225
Subtract 225 from both sides.
9x^{2}+90x=-222
Subtract 225 from 3 to get -222.
\frac{9x^{2}+90x}{9}=-\frac{222}{9}
Divide both sides by 9.
x^{2}+\frac{90}{9}x=-\frac{222}{9}
Dividing by 9 undoes the multiplication by 9.
x^{2}+10x=-\frac{222}{9}
Divide 90 by 9.
x^{2}+10x=-\frac{74}{3}
Reduce the fraction \frac{-222}{9} to lowest terms by extracting and canceling out 3.
x^{2}+10x+5^{2}=-\frac{74}{3}+5^{2}
Divide 10, the coefficient of the x term, by 2 to get 5. Then add the square of 5 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}+10x+25=-\frac{74}{3}+25
Square 5.
x^{2}+10x+25=\frac{1}{3}
Add -\frac{74}{3} to 25.
\left(x+5\right)^{2}=\frac{1}{3}
Factor x^{2}+10x+25. In general, when x^{2}+bx+c is a perfect square, it can always be factored as \left(x+\frac{b}{2}\right)^{2}.
\sqrt{\left(x+5\right)^{2}}=\sqrt{\frac{1}{3}}
Take the square root of both sides of the equation.
x+5=\frac{\sqrt{3}}{3} x+5=-\frac{\sqrt{3}}{3}
Simplify.
x=\frac{\sqrt{3}}{3}-5 x=-\frac{\sqrt{3}}{3}-5
Subtract 5 from both sides of the equation.