Solve for x
x = \frac{2 \sqrt{85}}{5} \approx 3.687817783
x = -\frac{2 \sqrt{85}}{5} \approx -3.687817783
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x^{2}=5.76+2.8^{2}
Calculate 2.4 to the power of 2 and get 5.76.
x^{2}=5.76+7.84
Calculate 2.8 to the power of 2 and get 7.84.
x^{2}=13.6
Add 5.76 and 7.84 to get 13.6.
x=\frac{2\sqrt{85}}{5} x=-\frac{2\sqrt{85}}{5}
Take the square root of both sides of the equation.
x^{2}=5.76+2.8^{2}
Calculate 2.4 to the power of 2 and get 5.76.
x^{2}=5.76+7.84
Calculate 2.8 to the power of 2 and get 7.84.
x^{2}=13.6
Add 5.76 and 7.84 to get 13.6.
x^{2}-13.6=0
Subtract 13.6 from both sides.
x=\frac{0±\sqrt{0^{2}-4\left(-13.6\right)}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -13.6 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\left(-13.6\right)}}{2}
Square 0.
x=\frac{0±\sqrt{54.4}}{2}
Multiply -4 times -13.6.
x=\frac{0±\frac{4\sqrt{85}}{5}}{2}
Take the square root of 54.4.
x=\frac{2\sqrt{85}}{5}
Now solve the equation x=\frac{0±\frac{4\sqrt{85}}{5}}{2} when ± is plus.
x=-\frac{2\sqrt{85}}{5}
Now solve the equation x=\frac{0±\frac{4\sqrt{85}}{5}}{2} when ± is minus.
x=\frac{2\sqrt{85}}{5} x=-\frac{2\sqrt{85}}{5}
The equation is now solved.
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