Solve for x
x=-9
x=1
Graph
Share
Copied to clipboard
\left(x-3\right)\times 4-\left(-\left(3+x\right)\times 5\right)=x+3+\left(x-3\right)\left(x+3\right)\left(-1\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+3,3-x,x-3.
4x-12-\left(-\left(3+x\right)\times 5\right)=x+3+\left(x-3\right)\left(x+3\right)\left(-1\right)
Use the distributive property to multiply x-3 by 4.
4x-12-\left(-5\left(3+x\right)\right)=x+3+\left(x-3\right)\left(x+3\right)\left(-1\right)
Multiply -1 and 5 to get -5.
4x-12-\left(-15-5x\right)=x+3+\left(x-3\right)\left(x+3\right)\left(-1\right)
Use the distributive property to multiply -5 by 3+x.
4x-12+15+5x=x+3+\left(x-3\right)\left(x+3\right)\left(-1\right)
To find the opposite of -15-5x, find the opposite of each term.
4x+3+5x=x+3+\left(x-3\right)\left(x+3\right)\left(-1\right)
Add -12 and 15 to get 3.
9x+3=x+3+\left(x-3\right)\left(x+3\right)\left(-1\right)
Combine 4x and 5x to get 9x.
9x+3=x+3+\left(x^{2}-9\right)\left(-1\right)
Use the distributive property to multiply x-3 by x+3 and combine like terms.
9x+3=x+3-x^{2}+9
Use the distributive property to multiply x^{2}-9 by -1.
9x+3=x+12-x^{2}
Add 3 and 9 to get 12.
9x+3-x=12-x^{2}
Subtract x from both sides.
8x+3=12-x^{2}
Combine 9x and -x to get 8x.
8x+3-12=-x^{2}
Subtract 12 from both sides.
8x-9=-x^{2}
Subtract 12 from 3 to get -9.
8x-9+x^{2}=0
Add x^{2} to both sides.
x^{2}+8x-9=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{-8±\sqrt{8^{2}-4\left(-9\right)}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 8 for b, and -9 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-8±\sqrt{64-4\left(-9\right)}}{2}
Square 8.
x=\frac{-8±\sqrt{64+36}}{2}
Multiply -4 times -9.
x=\frac{-8±\sqrt{100}}{2}
Add 64 to 36.
x=\frac{-8±10}{2}
Take the square root of 100.
x=\frac{2}{2}
Now solve the equation x=\frac{-8±10}{2} when ± is plus. Add -8 to 10.
x=1
Divide 2 by 2.
x=-\frac{18}{2}
Now solve the equation x=\frac{-8±10}{2} when ± is minus. Subtract 10 from -8.
x=-9
Divide -18 by 2.
x=1 x=-9
The equation is now solved.
\left(x-3\right)\times 4-\left(-\left(3+x\right)\times 5\right)=x+3+\left(x-3\right)\left(x+3\right)\left(-1\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+3,3-x,x-3.
4x-12-\left(-\left(3+x\right)\times 5\right)=x+3+\left(x-3\right)\left(x+3\right)\left(-1\right)
Use the distributive property to multiply x-3 by 4.
4x-12-\left(-5\left(3+x\right)\right)=x+3+\left(x-3\right)\left(x+3\right)\left(-1\right)
Multiply -1 and 5 to get -5.
4x-12-\left(-15-5x\right)=x+3+\left(x-3\right)\left(x+3\right)\left(-1\right)
Use the distributive property to multiply -5 by 3+x.
4x-12+15+5x=x+3+\left(x-3\right)\left(x+3\right)\left(-1\right)
To find the opposite of -15-5x, find the opposite of each term.
4x+3+5x=x+3+\left(x-3\right)\left(x+3\right)\left(-1\right)
Add -12 and 15 to get 3.
9x+3=x+3+\left(x-3\right)\left(x+3\right)\left(-1\right)
Combine 4x and 5x to get 9x.
9x+3=x+3+\left(x^{2}-9\right)\left(-1\right)
Use the distributive property to multiply x-3 by x+3 and combine like terms.
9x+3=x+3-x^{2}+9
Use the distributive property to multiply x^{2}-9 by -1.
9x+3=x+12-x^{2}
Add 3 and 9 to get 12.
9x+3-x=12-x^{2}
Subtract x from both sides.
8x+3=12-x^{2}
Combine 9x and -x to get 8x.
8x+3+x^{2}=12
Add x^{2} to both sides.
8x+x^{2}=12-3
Subtract 3 from both sides.
8x+x^{2}=9
Subtract 3 from 12 to get 9.
x^{2}+8x=9
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.
x^{2}+8x+4^{2}=9+4^{2}
Divide 8, the coefficient of the x term, by 2 to get 4. Then add the square of 4 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}+8x+16=9+16
Square 4.
x^{2}+8x+16=25
Add 9 to 16.
\left(x+4\right)^{2}=25
Factor x^{2}+8x+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+4\right)^{2}}=\sqrt{25}
Take the square root of both sides of the equation.
x+4=5 x+4=-5
Simplify.
x=1 x=-9
Subtract 4 from both sides of the equation.
Examples
Quadratic equation
{ x } ^ { 2 } - 4 x - 5 = 0
Trigonometry
4 \sin \theta \cos \theta = 2 \sin \theta
Linear equation
y = 3x + 4
Arithmetic
699 * 533
Matrix
\left[ \begin{array} { l l } { 2 } & { 3 } \\ { 5 } & { 4 } \end{array} \right] \left[ \begin{array} { l l l } { 2 } & { 0 } & { 3 } \\ { -1 } & { 1 } & { 5 } \end{array} \right]
Simultaneous equation
\left. \begin{cases} { 8x+2y = 46 } \\ { 7x+3y = 47 } \end{cases} \right.
Differentiation
\frac { d } { d x } \frac { ( 3 x ^ { 2 } - 2 ) } { ( x - 5 ) }
Integration
\int _ { 0 } ^ { 1 } x e ^ { - x ^ { 2 } } d x
Limits
\lim _{x \rightarrow-3} \frac{x^{2}-9}{x^{2}+2 x-3}