Solve for x
x=2\sqrt{19}\approx 8.717797887
x=-2\sqrt{19}\approx -8.717797887
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x^{2}+13=89
Add 6 and 7 to get 13.
x^{2}=89-13
Subtract 13 from both sides.
x^{2}=76
Subtract 13 from 89 to get 76.
x=2\sqrt{19} x=-2\sqrt{19}
Take the square root of both sides of the equation.
x^{2}+13=89
Add 6 and 7 to get 13.
x^{2}+13-89=0
Subtract 89 from both sides.
x^{2}-76=0
Subtract 89 from 13 to get -76.
x=\frac{0±\sqrt{0^{2}-4\left(-76\right)}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -76 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\left(-76\right)}}{2}
Square 0.
x=\frac{0±\sqrt{304}}{2}
Multiply -4 times -76.
x=\frac{0±4\sqrt{19}}{2}
Take the square root of 304.
x=2\sqrt{19}
Now solve the equation x=\frac{0±4\sqrt{19}}{2} when ± is plus.
x=-2\sqrt{19}
Now solve the equation x=\frac{0±4\sqrt{19}}{2} when ± is minus.
x=2\sqrt{19} x=-2\sqrt{19}
The equation is now solved.
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