Solve for x
x=\frac{2}{3}\approx 0.666666667
x=\frac{7}{9}\approx 0.777777778
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3\left(9x^{2}-12x+4\right)+2-3x=0
Use binomial theorem \left(a-b\right)^{2}=a^{2}-2ab+b^{2} to expand \left(3x-2\right)^{2}.
27x^{2}-36x+12+2-3x=0
Use the distributive property to multiply 3 by 9x^{2}-12x+4.
27x^{2}-36x+14-3x=0
Add 12 and 2 to get 14.
27x^{2}-39x+14=0
Combine -36x and -3x to get -39x.
a+b=-39 ab=27\times 14=378
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as 27x^{2}+ax+bx+14. To find a and b, set up a system to be solved.
-1,-378 -2,-189 -3,-126 -6,-63 -7,-54 -9,-42 -14,-27 -18,-21
Since ab is positive, a and b have the same sign. Since a+b is negative, a and b are both negative. List all such integer pairs that give product 378.
-1-378=-379 -2-189=-191 -3-126=-129 -6-63=-69 -7-54=-61 -9-42=-51 -14-27=-41 -18-21=-39
Calculate the sum for each pair.
a=-21 b=-18
The solution is the pair that gives sum -39.
\left(27x^{2}-21x\right)+\left(-18x+14\right)
Rewrite 27x^{2}-39x+14 as \left(27x^{2}-21x\right)+\left(-18x+14\right).
3x\left(9x-7\right)-2\left(9x-7\right)
Factor out 3x in the first and -2 in the second group.
\left(9x-7\right)\left(3x-2\right)
Factor out common term 9x-7 by using distributive property.
x=\frac{7}{9} x=\frac{2}{3}
To find equation solutions, solve 9x-7=0 and 3x-2=0.
3\left(9x^{2}-12x+4\right)+2-3x=0
Use binomial theorem \left(a-b\right)^{2}=a^{2}-2ab+b^{2} to expand \left(3x-2\right)^{2}.
27x^{2}-36x+12+2-3x=0
Use the distributive property to multiply 3 by 9x^{2}-12x+4.
27x^{2}-36x+14-3x=0
Add 12 and 2 to get 14.
27x^{2}-39x+14=0
Combine -36x and -3x to get -39x.
x=\frac{-\left(-39\right)±\sqrt{\left(-39\right)^{2}-4\times 27\times 14}}{2\times 27}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 27 for a, -39 for b, and 14 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-39\right)±\sqrt{1521-4\times 27\times 14}}{2\times 27}
Square -39.
x=\frac{-\left(-39\right)±\sqrt{1521-108\times 14}}{2\times 27}
Multiply -4 times 27.
x=\frac{-\left(-39\right)±\sqrt{1521-1512}}{2\times 27}
Multiply -108 times 14.
x=\frac{-\left(-39\right)±\sqrt{9}}{2\times 27}
Add 1521 to -1512.
x=\frac{-\left(-39\right)±3}{2\times 27}
Take the square root of 9.
x=\frac{39±3}{2\times 27}
The opposite of -39 is 39.
x=\frac{39±3}{54}
Multiply 2 times 27.
x=\frac{42}{54}
Now solve the equation x=\frac{39±3}{54} when ± is plus. Add 39 to 3.
x=\frac{7}{9}
Reduce the fraction \frac{42}{54} to lowest terms by extracting and canceling out 6.
x=\frac{36}{54}
Now solve the equation x=\frac{39±3}{54} when ± is minus. Subtract 3 from 39.
x=\frac{2}{3}
Reduce the fraction \frac{36}{54} to lowest terms by extracting and canceling out 18.
x=\frac{7}{9} x=\frac{2}{3}
The equation is now solved.
3\left(9x^{2}-12x+4\right)+2-3x=0
Use binomial theorem \left(a-b\right)^{2}=a^{2}-2ab+b^{2} to expand \left(3x-2\right)^{2}.
27x^{2}-36x+12+2-3x=0
Use the distributive property to multiply 3 by 9x^{2}-12x+4.
27x^{2}-36x+14-3x=0
Add 12 and 2 to get 14.
27x^{2}-39x+14=0
Combine -36x and -3x to get -39x.
27x^{2}-39x=-14
Subtract 14 from both sides. Anything subtracted from zero gives its negation.
\frac{27x^{2}-39x}{27}=-\frac{14}{27}
Divide both sides by 27.
x^{2}+\left(-\frac{39}{27}\right)x=-\frac{14}{27}
Dividing by 27 undoes the multiplication by 27.
x^{2}-\frac{13}{9}x=-\frac{14}{27}
Reduce the fraction \frac{-39}{27} to lowest terms by extracting and canceling out 3.
x^{2}-\frac{13}{9}x+\left(-\frac{13}{18}\right)^{2}=-\frac{14}{27}+\left(-\frac{13}{18}\right)^{2}
Divide -\frac{13}{9}, the coefficient of the x term, by 2 to get -\frac{13}{18}. Then add the square of -\frac{13}{18} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-\frac{13}{9}x+\frac{169}{324}=-\frac{14}{27}+\frac{169}{324}
Square -\frac{13}{18} by squaring both the numerator and the denominator of the fraction.
x^{2}-\frac{13}{9}x+\frac{169}{324}=\frac{1}{324}
Add -\frac{14}{27} to \frac{169}{324} by finding a common denominator and adding the numerators. Then reduce the fraction to lowest terms if possible.
\left(x-\frac{13}{18}\right)^{2}=\frac{1}{324}
Factor x^{2}-\frac{13}{9}x+\frac{169}{324}. 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{13}{18}\right)^{2}}=\sqrt{\frac{1}{324}}
Take the square root of both sides of the equation.
x-\frac{13}{18}=\frac{1}{18} x-\frac{13}{18}=-\frac{1}{18}
Simplify.
x=\frac{7}{9} x=\frac{2}{3}
Add \frac{13}{18} to both sides of the equation.
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Matrix
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Simultaneous equation
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Differentiation
\frac { d } { d x } \frac { ( 3 x ^ { 2 } - 2 ) } { ( x - 5 ) }
Integration
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Limits
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