Skip to main content
Solve for x
Tick mark Image
Graph

Similar Problems from Web Search

Share

\left(x-4\right)\left(x+4\right)=3\times 3
Variable x cannot be equal to 4 since division by zero is not defined. Multiply both sides of the equation by 3\left(x-4\right), the least common multiple of 3,x-4.
x^{2}-16=3\times 3
Consider \left(x-4\right)\left(x+4\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 4.
x^{2}-16=9
Multiply 3 and 3 to get 9.
x^{2}=9+16
Add 16 to both sides.
x^{2}=25
Add 9 and 16 to get 25.
x=5 x=-5
Take the square root of both sides of the equation.
\left(x-4\right)\left(x+4\right)=3\times 3
Variable x cannot be equal to 4 since division by zero is not defined. Multiply both sides of the equation by 3\left(x-4\right), the least common multiple of 3,x-4.
x^{2}-16=3\times 3
Consider \left(x-4\right)\left(x+4\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 4.
x^{2}-16=9
Multiply 3 and 3 to get 9.
x^{2}-16-9=0
Subtract 9 from both sides.
x^{2}-25=0
Subtract 9 from -16 to get -25.
x=\frac{0±\sqrt{0^{2}-4\left(-25\right)}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -25 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\left(-25\right)}}{2}
Square 0.
x=\frac{0±\sqrt{100}}{2}
Multiply -4 times -25.
x=\frac{0±10}{2}
Take the square root of 100.
x=5
Now solve the equation x=\frac{0±10}{2} when ± is plus. Divide 10 by 2.
x=-5
Now solve the equation x=\frac{0±10}{2} when ± is minus. Divide -10 by 2.
x=5 x=-5
The equation is now solved.