Solve for m
m = \frac{4 \sqrt{7}}{7} \approx 1.511857892
m = -\frac{4 \sqrt{7}}{7} \approx -1.511857892
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-7m^{2}+16=0
Combine m^{2} and -8m^{2} to get -7m^{2}.
-7m^{2}=-16
Subtract 16 from both sides. Anything subtracted from zero gives its negation.
m^{2}=\frac{-16}{-7}
Divide both sides by -7.
m^{2}=\frac{16}{7}
Fraction \frac{-16}{-7} can be simplified to \frac{16}{7} by removing the negative sign from both the numerator and the denominator.
m=\frac{4\sqrt{7}}{7} m=-\frac{4\sqrt{7}}{7}
Take the square root of both sides of the equation.
-7m^{2}+16=0
Combine m^{2} and -8m^{2} to get -7m^{2}.
m=\frac{0±\sqrt{0^{2}-4\left(-7\right)\times 16}}{2\left(-7\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -7 for a, 0 for b, and 16 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
m=\frac{0±\sqrt{-4\left(-7\right)\times 16}}{2\left(-7\right)}
Square 0.
m=\frac{0±\sqrt{28\times 16}}{2\left(-7\right)}
Multiply -4 times -7.
m=\frac{0±\sqrt{448}}{2\left(-7\right)}
Multiply 28 times 16.
m=\frac{0±8\sqrt{7}}{2\left(-7\right)}
Take the square root of 448.
m=\frac{0±8\sqrt{7}}{-14}
Multiply 2 times -7.
m=-\frac{4\sqrt{7}}{7}
Now solve the equation m=\frac{0±8\sqrt{7}}{-14} when ± is plus.
m=\frac{4\sqrt{7}}{7}
Now solve the equation m=\frac{0±8\sqrt{7}}{-14} when ± is minus.
m=-\frac{4\sqrt{7}}{7} m=\frac{4\sqrt{7}}{7}
The equation is now solved.
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