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5x+\left(x-3\right)\times 5=\left(x-3\right)\left(x+3\right)-\left(-\left(3+x\right)x\right)
Variable x cannot be equal to any of the values -3,3 since division by zero is not defined. Multiply both sides of the equation by \left(x-3\right)\left(x+3\right), the least common multiple of x^{2}-9,x+3,3-x.
5x+5x-15=\left(x-3\right)\left(x+3\right)-\left(-\left(3+x\right)x\right)
Use the distributive property to multiply x-3 by 5.
10x-15=\left(x-3\right)\left(x+3\right)-\left(-\left(3+x\right)x\right)
Combine 5x and 5x to get 10x.
10x-15=x^{2}-9-\left(-\left(3+x\right)x\right)
Consider \left(x-3\right)\left(x+3\right). Multiplication can be transformed into difference of squares using the rule: \left(a-b\right)\left(a+b\right)=a^{2}-b^{2}. Square 3.
10x-15=x^{2}-9-\left(-3-x\right)x
Use the distributive property to multiply -1 by 3+x.
10x-15=x^{2}-9-\left(-3x-x^{2}\right)
Use the distributive property to multiply -3-x by x.
10x-15=x^{2}-9+3x+x^{2}
To find the opposite of -3x-x^{2}, find the opposite of each term.
10x-15=2x^{2}-9+3x
Combine x^{2} and x^{2} to get 2x^{2}.
10x-15-2x^{2}=-9+3x
Subtract 2x^{2} from both sides.
10x-15-2x^{2}-\left(-9\right)=3x
Subtract -9 from both sides.
10x-15-2x^{2}+9=3x
The opposite of -9 is 9.
10x-15-2x^{2}+9-3x=0
Subtract 3x from both sides.
10x-6-2x^{2}-3x=0
Add -15 and 9 to get -6.
7x-6-2x^{2}=0
Combine 10x and -3x to get 7x.
-2x^{2}+7x-6=0
Rearrange the polynomial to put it in standard form. Place the terms in order from highest to lowest power.
a+b=7 ab=-2\left(-6\right)=12
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as -2x^{2}+ax+bx-6. To find a and b, set up a system to be solved.
1,12 2,6 3,4
Since ab is positive, a and b have the same sign. Since a+b is positive, a and b are both positive. List all such integer pairs that give product 12.
1+12=13 2+6=8 3+4=7
Calculate the sum for each pair.
a=4 b=3
The solution is the pair that gives sum 7.
\left(-2x^{2}+4x\right)+\left(3x-6\right)
Rewrite -2x^{2}+7x-6 as \left(-2x^{2}+4x\right)+\left(3x-6\right).
2x\left(-x+2\right)-3\left(-x+2\right)
Factor out 2x in the first and -3 in the second group.
\left(-x+2\right)\left(2x-3\right)
Factor out common term -x+2 by using distributive property.
x=2 x=\frac{3}{2}
To find equation solutions, solve -x+2=0 and 2x-3=0.
5x+\left(x-3\right)\times 5=\left(x-3\right)\left(x+3\right)-\left(-\left(3+x\right)x\right)
Variable x cannot be equal to any of the values -3,3 since division by zero is not defined. Multiply both sides of the equation by \left(x-3\right)\left(x+3\right), the least common multiple of x^{2}-9,x+3,3-x.
5x+5x-15=\left(x-3\right)\left(x+3\right)-\left(-\left(3+x\right)x\right)
Use the distributive property to multiply x-3 by 5.
10x-15=\left(x-3\right)\left(x+3\right)-\left(-\left(3+x\right)x\right)
Combine 5x and 5x to get 10x.
10x-15=x^{2}-9-\left(-\left(3+x\right)x\right)
Consider \left(x-3\right)\left(x+3\right). Multiplication can be transformed into difference of squares using the rule: \left(a-b\right)\left(a+b\right)=a^{2}-b^{2}. Square 3.
10x-15=x^{2}-9-\left(-3-x\right)x
Use the distributive property to multiply -1 by 3+x.
10x-15=x^{2}-9-\left(-3x-x^{2}\right)
Use the distributive property to multiply -3-x by x.
10x-15=x^{2}-9+3x+x^{2}
To find the opposite of -3x-x^{2}, find the opposite of each term.
10x-15=2x^{2}-9+3x
Combine x^{2} and x^{2} to get 2x^{2}.
10x-15-2x^{2}=-9+3x
Subtract 2x^{2} from both sides.
10x-15-2x^{2}-\left(-9\right)=3x
Subtract -9 from both sides.
10x-15-2x^{2}+9=3x
The opposite of -9 is 9.
10x-15-2x^{2}+9-3x=0
Subtract 3x from both sides.
10x-6-2x^{2}-3x=0
Add -15 and 9 to get -6.
7x-6-2x^{2}=0
Combine 10x and -3x to get 7x.
-2x^{2}+7x-6=0
All equations of the form ax^{2}+bx+c=0 can be solved using the quadratic formula: \frac{-b±\sqrt{b^{2}-4ac}}{2a}. The quadratic formula gives two solutions, one when ± is addition and one when it is subtraction.
x=\frac{-7±\sqrt{7^{2}-4\left(-2\right)\left(-6\right)}}{2\left(-2\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -2 for a, 7 for b, and -6 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-7±\sqrt{49-4\left(-2\right)\left(-6\right)}}{2\left(-2\right)}
Square 7.
x=\frac{-7±\sqrt{49+8\left(-6\right)}}{2\left(-2\right)}
Multiply -4 times -2.
x=\frac{-7±\sqrt{49-48}}{2\left(-2\right)}
Multiply 8 times -6.
x=\frac{-7±\sqrt{1}}{2\left(-2\right)}
Add 49 to -48.
x=\frac{-7±1}{2\left(-2\right)}
Take the square root of 1.
x=\frac{-7±1}{-4}
Multiply 2 times -2.
x=-\frac{6}{-4}
Now solve the equation x=\frac{-7±1}{-4} when ± is plus. Add -7 to 1.
x=\frac{3}{2}
Reduce the fraction \frac{-6}{-4} to lowest terms by extracting and canceling out 2.
x=-\frac{8}{-4}
Now solve the equation x=\frac{-7±1}{-4} when ± is minus. Subtract 1 from -7.
x=2
Divide -8 by -4.
x=\frac{3}{2} x=2
The equation is now solved.
5x+\left(x-3\right)\times 5=\left(x-3\right)\left(x+3\right)-\left(-\left(3+x\right)x\right)
Variable x cannot be equal to any of the values -3,3 since division by zero is not defined. Multiply both sides of the equation by \left(x-3\right)\left(x+3\right), the least common multiple of x^{2}-9,x+3,3-x.
5x+5x-15=\left(x-3\right)\left(x+3\right)-\left(-\left(3+x\right)x\right)
Use the distributive property to multiply x-3 by 5.
10x-15=\left(x-3\right)\left(x+3\right)-\left(-\left(3+x\right)x\right)
Combine 5x and 5x to get 10x.
10x-15=x^{2}-9-\left(-\left(3+x\right)x\right)
Consider \left(x-3\right)\left(x+3\right). Multiplication can be transformed into difference of squares using the rule: \left(a-b\right)\left(a+b\right)=a^{2}-b^{2}. Square 3.
10x-15=x^{2}-9-\left(-3-x\right)x
Use the distributive property to multiply -1 by 3+x.
10x-15=x^{2}-9-\left(-3x-x^{2}\right)
Use the distributive property to multiply -3-x by x.
10x-15=x^{2}-9+3x+x^{2}
To find the opposite of -3x-x^{2}, find the opposite of each term.
10x-15=2x^{2}-9+3x
Combine x^{2} and x^{2} to get 2x^{2}.
10x-15-2x^{2}=-9+3x
Subtract 2x^{2} from both sides.
10x-15-2x^{2}-3x=-9
Subtract 3x from both sides.
7x-15-2x^{2}=-9
Combine 10x and -3x to get 7x.
7x-2x^{2}=-9+15
Add 15 to both sides.
7x-2x^{2}=6
Add -9 and 15 to get 6.
-2x^{2}+7x=6
Quadratic equations such as this one can be solved by completing the square. In order to complete the square, the equation must first be in the form x^{2}+bx=c.
\frac{-2x^{2}+7x}{-2}=\frac{6}{-2}
Divide both sides by -2.
x^{2}+\frac{7}{-2}x=\frac{6}{-2}
Dividing by -2 undoes the multiplication by -2.
x^{2}-\frac{7}{2}x=\frac{6}{-2}
Divide 7 by -2.
x^{2}-\frac{7}{2}x=-3
Divide 6 by -2.
x^{2}-\frac{7}{2}x+\left(-\frac{7}{4}\right)^{2}=-3+\left(-\frac{7}{4}\right)^{2}
Divide -\frac{7}{2}, the coefficient of the x term, by 2 to get -\frac{7}{4}. Then add the square of -\frac{7}{4} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-\frac{7}{2}x+\frac{49}{16}=-3+\frac{49}{16}
Square -\frac{7}{4} by squaring both the numerator and the denominator of the fraction.
x^{2}-\frac{7}{2}x+\frac{49}{16}=\frac{1}{16}
Add -3 to \frac{49}{16}.
\left(x-\frac{7}{4}\right)^{2}=\frac{1}{16}
Factor x^{2}-\frac{7}{2}x+\frac{49}{16}. In general, when x^{2}+bx+c is a perfect square, it can always be factored as \left(x+\frac{b}{2}\right)^{2}.
\sqrt{\left(x-\frac{7}{4}\right)^{2}}=\sqrt{\frac{1}{16}}
Take the square root of both sides of the equation.
x-\frac{7}{4}=\frac{1}{4} x-\frac{7}{4}=-\frac{1}{4}
Simplify.
x=2 x=\frac{3}{2}
Add \frac{7}{4} to both sides of the equation.