Solve for x
x=-10
x=10
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3\left(x-5\right)\left(x+5\right)\times \frac{10}{3}+\left(3x-15\right)\left(5-x\right)=\left(3x+15\right)\left(x+5\right)
Variable x cannot be equal to any of the values -5,5 since division by zero is not defined. Multiply both sides of the equation by 3\left(x-5\right)\left(x+5\right), the least common multiple of 3,x+5,x-5.
\left(3x-15\right)\left(x+5\right)\times \frac{10}{3}+\left(3x-15\right)\left(5-x\right)=\left(3x+15\right)\left(x+5\right)
Use the distributive property to multiply 3 by x-5.
\left(3x^{2}-75\right)\times \frac{10}{3}+\left(3x-15\right)\left(5-x\right)=\left(3x+15\right)\left(x+5\right)
Use the distributive property to multiply 3x-15 by x+5 and combine like terms.
10x^{2}-250+\left(3x-15\right)\left(5-x\right)=\left(3x+15\right)\left(x+5\right)
Use the distributive property to multiply 3x^{2}-75 by \frac{10}{3}.
10x^{2}-250+30x-3x^{2}-75=\left(3x+15\right)\left(x+5\right)
Use the distributive property to multiply 3x-15 by 5-x and combine like terms.
7x^{2}-250+30x-75=\left(3x+15\right)\left(x+5\right)
Combine 10x^{2} and -3x^{2} to get 7x^{2}.
7x^{2}-325+30x=\left(3x+15\right)\left(x+5\right)
Subtract 75 from -250 to get -325.
7x^{2}-325+30x=3x^{2}+30x+75
Use the distributive property to multiply 3x+15 by x+5 and combine like terms.
7x^{2}-325+30x-3x^{2}=30x+75
Subtract 3x^{2} from both sides.
4x^{2}-325+30x=30x+75
Combine 7x^{2} and -3x^{2} to get 4x^{2}.
4x^{2}-325+30x-30x=75
Subtract 30x from both sides.
4x^{2}-325=75
Combine 30x and -30x to get 0.
4x^{2}=75+325
Add 325 to both sides.
4x^{2}=400
Add 75 and 325 to get 400.
x^{2}=\frac{400}{4}
Divide both sides by 4.
x^{2}=100
Divide 400 by 4 to get 100.
x=10 x=-10
Take the square root of both sides of the equation.
3\left(x-5\right)\left(x+5\right)\times \frac{10}{3}+\left(3x-15\right)\left(5-x\right)=\left(3x+15\right)\left(x+5\right)
Variable x cannot be equal to any of the values -5,5 since division by zero is not defined. Multiply both sides of the equation by 3\left(x-5\right)\left(x+5\right), the least common multiple of 3,x+5,x-5.
\left(3x-15\right)\left(x+5\right)\times \frac{10}{3}+\left(3x-15\right)\left(5-x\right)=\left(3x+15\right)\left(x+5\right)
Use the distributive property to multiply 3 by x-5.
\left(3x^{2}-75\right)\times \frac{10}{3}+\left(3x-15\right)\left(5-x\right)=\left(3x+15\right)\left(x+5\right)
Use the distributive property to multiply 3x-15 by x+5 and combine like terms.
10x^{2}-250+\left(3x-15\right)\left(5-x\right)=\left(3x+15\right)\left(x+5\right)
Use the distributive property to multiply 3x^{2}-75 by \frac{10}{3}.
10x^{2}-250+30x-3x^{2}-75=\left(3x+15\right)\left(x+5\right)
Use the distributive property to multiply 3x-15 by 5-x and combine like terms.
7x^{2}-250+30x-75=\left(3x+15\right)\left(x+5\right)
Combine 10x^{2} and -3x^{2} to get 7x^{2}.
7x^{2}-325+30x=\left(3x+15\right)\left(x+5\right)
Subtract 75 from -250 to get -325.
7x^{2}-325+30x=3x^{2}+30x+75
Use the distributive property to multiply 3x+15 by x+5 and combine like terms.
7x^{2}-325+30x-3x^{2}=30x+75
Subtract 3x^{2} from both sides.
4x^{2}-325+30x=30x+75
Combine 7x^{2} and -3x^{2} to get 4x^{2}.
4x^{2}-325+30x-30x=75
Subtract 30x from both sides.
4x^{2}-325=75
Combine 30x and -30x to get 0.
4x^{2}-325-75=0
Subtract 75 from both sides.
4x^{2}-400=0
Subtract 75 from -325 to get -400.
x=\frac{0±\sqrt{0^{2}-4\times 4\left(-400\right)}}{2\times 4}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 4 for a, 0 for b, and -400 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\times 4\left(-400\right)}}{2\times 4}
Square 0.
x=\frac{0±\sqrt{-16\left(-400\right)}}{2\times 4}
Multiply -4 times 4.
x=\frac{0±\sqrt{6400}}{2\times 4}
Multiply -16 times -400.
x=\frac{0±80}{2\times 4}
Take the square root of 6400.
x=\frac{0±80}{8}
Multiply 2 times 4.
x=10
Now solve the equation x=\frac{0±80}{8} when ± is plus. Divide 80 by 8.
x=-10
Now solve the equation x=\frac{0±80}{8} when ± is minus. Divide -80 by 8.
x=10 x=-10
The equation is now solved.
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