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8\times 5=3x\times 3x
Variable x cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by 24x, the least common multiple of 3x,8.
8\times 5=\left(3x\right)^{2}
Multiply 3x and 3x to get \left(3x\right)^{2}.
40=\left(3x\right)^{2}
Multiply 8 and 5 to get 40.
40=3^{2}x^{2}
Expand \left(3x\right)^{2}.
40=9x^{2}
Calculate 3 to the power of 2 and get 9.
9x^{2}=40
Swap sides so that all variable terms are on the left hand side.
x^{2}=\frac{40}{9}
Divide both sides by 9.
x=\frac{2\sqrt{10}}{3} x=-\frac{2\sqrt{10}}{3}
Take the square root of both sides of the equation.
8\times 5=3x\times 3x
Variable x cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by 24x, the least common multiple of 3x,8.
8\times 5=\left(3x\right)^{2}
Multiply 3x and 3x to get \left(3x\right)^{2}.
40=\left(3x\right)^{2}
Multiply 8 and 5 to get 40.
40=3^{2}x^{2}
Expand \left(3x\right)^{2}.
40=9x^{2}
Calculate 3 to the power of 2 and get 9.
9x^{2}=40
Swap sides so that all variable terms are on the left hand side.
9x^{2}-40=0
Subtract 40 from both sides.
x=\frac{0±\sqrt{0^{2}-4\times 9\left(-40\right)}}{2\times 9}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 9 for a, 0 for b, and -40 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\times 9\left(-40\right)}}{2\times 9}
Square 0.
x=\frac{0±\sqrt{-36\left(-40\right)}}{2\times 9}
Multiply -4 times 9.
x=\frac{0±\sqrt{1440}}{2\times 9}
Multiply -36 times -40.
x=\frac{0±12\sqrt{10}}{2\times 9}
Take the square root of 1440.
x=\frac{0±12\sqrt{10}}{18}
Multiply 2 times 9.
x=\frac{2\sqrt{10}}{3}
Now solve the equation x=\frac{0±12\sqrt{10}}{18} when ± is plus.
x=-\frac{2\sqrt{10}}{3}
Now solve the equation x=\frac{0±12\sqrt{10}}{18} when ± is minus.
x=\frac{2\sqrt{10}}{3} x=-\frac{2\sqrt{10}}{3}
The equation is now solved.