Solve for x
x=\frac{\sqrt{41}}{2}-3\approx 0.201562119
x=-\frac{\sqrt{41}}{2}-3\approx -6.201562119
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2\times 2\left(x+3\right)^{2}=41
Multiply x+3 and x+3 to get \left(x+3\right)^{2}.
4\left(x+3\right)^{2}=41
Multiply 2 and 2 to get 4.
4\left(x^{2}+6x+9\right)=41
Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(x+3\right)^{2}.
4x^{2}+24x+36=41
Use the distributive property to multiply 4 by x^{2}+6x+9.
4x^{2}+24x+36-41=0
Subtract 41 from both sides.
4x^{2}+24x-5=0
Subtract 41 from 36 to get -5.
x=\frac{-24±\sqrt{24^{2}-4\times 4\left(-5\right)}}{2\times 4}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 4 for a, 24 for b, and -5 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-24±\sqrt{576-4\times 4\left(-5\right)}}{2\times 4}
Square 24.
x=\frac{-24±\sqrt{576-16\left(-5\right)}}{2\times 4}
Multiply -4 times 4.
x=\frac{-24±\sqrt{576+80}}{2\times 4}
Multiply -16 times -5.
x=\frac{-24±\sqrt{656}}{2\times 4}
Add 576 to 80.
x=\frac{-24±4\sqrt{41}}{2\times 4}
Take the square root of 656.
x=\frac{-24±4\sqrt{41}}{8}
Multiply 2 times 4.
x=\frac{4\sqrt{41}-24}{8}
Now solve the equation x=\frac{-24±4\sqrt{41}}{8} when ± is plus. Add -24 to 4\sqrt{41}.
x=\frac{\sqrt{41}}{2}-3
Divide -24+4\sqrt{41} by 8.
x=\frac{-4\sqrt{41}-24}{8}
Now solve the equation x=\frac{-24±4\sqrt{41}}{8} when ± is minus. Subtract 4\sqrt{41} from -24.
x=-\frac{\sqrt{41}}{2}-3
Divide -24-4\sqrt{41} by 8.
x=\frac{\sqrt{41}}{2}-3 x=-\frac{\sqrt{41}}{2}-3
The equation is now solved.
2\times 2\left(x+3\right)^{2}=41
Multiply x+3 and x+3 to get \left(x+3\right)^{2}.
4\left(x+3\right)^{2}=41
Multiply 2 and 2 to get 4.
4\left(x^{2}+6x+9\right)=41
Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(x+3\right)^{2}.
4x^{2}+24x+36=41
Use the distributive property to multiply 4 by x^{2}+6x+9.
4x^{2}+24x=41-36
Subtract 36 from both sides.
4x^{2}+24x=5
Subtract 36 from 41 to get 5.
\frac{4x^{2}+24x}{4}=\frac{5}{4}
Divide both sides by 4.
x^{2}+\frac{24}{4}x=\frac{5}{4}
Dividing by 4 undoes the multiplication by 4.
x^{2}+6x=\frac{5}{4}
Divide 24 by 4.
x^{2}+6x+3^{2}=\frac{5}{4}+3^{2}
Divide 6, the coefficient of the x term, by 2 to get 3. Then add the square of 3 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}+6x+9=\frac{5}{4}+9
Square 3.
x^{2}+6x+9=\frac{41}{4}
Add \frac{5}{4} to 9.
\left(x+3\right)^{2}=\frac{41}{4}
Factor x^{2}+6x+9. 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+3\right)^{2}}=\sqrt{\frac{41}{4}}
Take the square root of both sides of the equation.
x+3=\frac{\sqrt{41}}{2} x+3=-\frac{\sqrt{41}}{2}
Simplify.
x=\frac{\sqrt{41}}{2}-3 x=-\frac{\sqrt{41}}{2}-3
Subtract 3 from both sides of the equation.
Examples
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{ 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}