Solve for x
x=1
x=-6
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4x^{2}+20x+25+2016=2065
Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(2x+5\right)^{2}.
4x^{2}+20x+2041=2065
Add 25 and 2016 to get 2041.
4x^{2}+20x+2041-2065=0
Subtract 2065 from both sides.
4x^{2}+20x-24=0
Subtract 2065 from 2041 to get -24.
x^{2}+5x-6=0
Divide both sides by 4.
a+b=5 ab=1\left(-6\right)=-6
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as x^{2}+ax+bx-6. To find a and b, set up a system to be solved.
-1,6 -2,3
Since ab is negative, a and b have the opposite signs. Since a+b is positive, the positive number has greater absolute value than the negative. List all such integer pairs that give product -6.
-1+6=5 -2+3=1
Calculate the sum for each pair.
a=-1 b=6
The solution is the pair that gives sum 5.
\left(x^{2}-x\right)+\left(6x-6\right)
Rewrite x^{2}+5x-6 as \left(x^{2}-x\right)+\left(6x-6\right).
x\left(x-1\right)+6\left(x-1\right)
Factor out x in the first and 6 in the second group.
\left(x-1\right)\left(x+6\right)
Factor out common term x-1 by using distributive property.
x=1 x=-6
To find equation solutions, solve x-1=0 and x+6=0.
4x^{2}+20x+25+2016=2065
Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(2x+5\right)^{2}.
4x^{2}+20x+2041=2065
Add 25 and 2016 to get 2041.
4x^{2}+20x+2041-2065=0
Subtract 2065 from both sides.
4x^{2}+20x-24=0
Subtract 2065 from 2041 to get -24.
x=\frac{-20±\sqrt{20^{2}-4\times 4\left(-24\right)}}{2\times 4}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 4 for a, 20 for b, and -24 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-20±\sqrt{400-4\times 4\left(-24\right)}}{2\times 4}
Square 20.
x=\frac{-20±\sqrt{400-16\left(-24\right)}}{2\times 4}
Multiply -4 times 4.
x=\frac{-20±\sqrt{400+384}}{2\times 4}
Multiply -16 times -24.
x=\frac{-20±\sqrt{784}}{2\times 4}
Add 400 to 384.
x=\frac{-20±28}{2\times 4}
Take the square root of 784.
x=\frac{-20±28}{8}
Multiply 2 times 4.
x=\frac{8}{8}
Now solve the equation x=\frac{-20±28}{8} when ± is plus. Add -20 to 28.
x=1
Divide 8 by 8.
x=-\frac{48}{8}
Now solve the equation x=\frac{-20±28}{8} when ± is minus. Subtract 28 from -20.
x=-6
Divide -48 by 8.
x=1 x=-6
The equation is now solved.
4x^{2}+20x+25+2016=2065
Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(2x+5\right)^{2}.
4x^{2}+20x+2041=2065
Add 25 and 2016 to get 2041.
4x^{2}+20x=2065-2041
Subtract 2041 from both sides.
4x^{2}+20x=24
Subtract 2041 from 2065 to get 24.
\frac{4x^{2}+20x}{4}=\frac{24}{4}
Divide both sides by 4.
x^{2}+\frac{20}{4}x=\frac{24}{4}
Dividing by 4 undoes the multiplication by 4.
x^{2}+5x=\frac{24}{4}
Divide 20 by 4.
x^{2}+5x=6
Divide 24 by 4.
x^{2}+5x+\left(\frac{5}{2}\right)^{2}=6+\left(\frac{5}{2}\right)^{2}
Divide 5, the coefficient of the x term, by 2 to get \frac{5}{2}. Then add the square of \frac{5}{2} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}+5x+\frac{25}{4}=6+\frac{25}{4}
Square \frac{5}{2} by squaring both the numerator and the denominator of the fraction.
x^{2}+5x+\frac{25}{4}=\frac{49}{4}
Add 6 to \frac{25}{4}.
\left(x+\frac{5}{2}\right)^{2}=\frac{49}{4}
Factor x^{2}+5x+\frac{25}{4}. 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{5}{2}\right)^{2}}=\sqrt{\frac{49}{4}}
Take the square root of both sides of the equation.
x+\frac{5}{2}=\frac{7}{2} x+\frac{5}{2}=-\frac{7}{2}
Simplify.
x=1 x=-6
Subtract \frac{5}{2} from both sides of the equation.
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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
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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
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