Solve for x
x=\sqrt{43}\approx 6.557438524
x=-\sqrt{43}\approx -6.557438524
Graph
Share
Copied to clipboard
2x^{2}-43-x^{2}=0
Subtract x^{2} from both sides.
x^{2}-43=0
Combine 2x^{2} and -x^{2} to get x^{2}.
x^{2}=43
Add 43 to both sides. Anything plus zero gives itself.
x=\sqrt{43} x=-\sqrt{43}
Take the square root of both sides of the equation.
2x^{2}-43-x^{2}=0
Subtract x^{2} from both sides.
x^{2}-43=0
Combine 2x^{2} and -x^{2} to get x^{2}.
x=\frac{0±\sqrt{0^{2}-4\left(-43\right)}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -43 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\left(-43\right)}}{2}
Square 0.
x=\frac{0±\sqrt{172}}{2}
Multiply -4 times -43.
x=\frac{0±2\sqrt{43}}{2}
Take the square root of 172.
x=\sqrt{43}
Now solve the equation x=\frac{0±2\sqrt{43}}{2} when ± is plus.
x=-\sqrt{43}
Now solve the equation x=\frac{0±2\sqrt{43}}{2} when ± is minus.
x=\sqrt{43} x=-\sqrt{43}
The equation is now solved.
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}