Solve for y
y=\frac{1}{3}\approx 0.333333333
Graph
Share
Copied to clipboard
\left(3y+1\right)^{2}=\left(2\sqrt{3y}\right)^{2}
Square both sides of the equation.
9y^{2}+6y+1=\left(2\sqrt{3y}\right)^{2}
Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(3y+1\right)^{2}.
9y^{2}+6y+1=2^{2}\left(\sqrt{3y}\right)^{2}
Expand \left(2\sqrt{3y}\right)^{2}.
9y^{2}+6y+1=4\left(\sqrt{3y}\right)^{2}
Calculate 2 to the power of 2 and get 4.
9y^{2}+6y+1=4\times 3y
Calculate \sqrt{3y} to the power of 2 and get 3y.
9y^{2}+6y+1=12y
Multiply 4 and 3 to get 12.
9y^{2}+6y+1-12y=0
Subtract 12y from both sides.
9y^{2}-6y+1=0
Combine 6y and -12y to get -6y.
a+b=-6 ab=9\times 1=9
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as 9y^{2}+ay+by+1. To find a and b, set up a system to be solved.
-1,-9 -3,-3
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 9.
-1-9=-10 -3-3=-6
Calculate the sum for each pair.
a=-3 b=-3
The solution is the pair that gives sum -6.
\left(9y^{2}-3y\right)+\left(-3y+1\right)
Rewrite 9y^{2}-6y+1 as \left(9y^{2}-3y\right)+\left(-3y+1\right).
3y\left(3y-1\right)-\left(3y-1\right)
Factor out 3y in the first and -1 in the second group.
\left(3y-1\right)\left(3y-1\right)
Factor out common term 3y-1 by using distributive property.
\left(3y-1\right)^{2}
Rewrite as a binomial square.
y=\frac{1}{3}
To find equation solution, solve 3y-1=0.
3\times \frac{1}{3}+1=2\sqrt{3\times \frac{1}{3}}
Substitute \frac{1}{3} for y in the equation 3y+1=2\sqrt{3y}.
2=2
Simplify. The value y=\frac{1}{3} satisfies the equation.
y=\frac{1}{3}
Equation 3y+1=2\sqrt{3y} has a unique solution.
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}