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xx-4=5
Variable x cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by 4x, the least common multiple of 4,x,4x.
x^{2}-4=5
Multiply x and x to get x^{2}.
x^{2}=5+4
Add 4 to both sides.
x^{2}=9
Add 5 and 4 to get 9.
x=3 x=-3
Take the square root of both sides of the equation.
xx-4=5
Variable x cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by 4x, the least common multiple of 4,x,4x.
x^{2}-4=5
Multiply x and x to get x^{2}.
x^{2}-4-5=0
Subtract 5 from both sides.
x^{2}-9=0
Subtract 5 from -4 to get -9.
x=\frac{0±\sqrt{0^{2}-4\left(-9\right)}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -9 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\left(-9\right)}}{2}
Square 0.
x=\frac{0±\sqrt{36}}{2}
Multiply -4 times -9.
x=\frac{0±6}{2}
Take the square root of 36.
x=3
Now solve the equation x=\frac{0±6}{2} when ± is plus. Divide 6 by 2.
x=-3
Now solve the equation x=\frac{0±6}{2} when ± is minus. Divide -6 by 2.
x=3 x=-3
The equation is now solved.