Solve for b
b=\frac{1}{2}=0.5
b = \frac{3}{2} = 1\frac{1}{2} = 1.5
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b=\frac{2\times 4b}{4b}-\frac{3}{4b}
To add or subtract expressions, expand them to make their denominators the same. Multiply 2 times \frac{4b}{4b}.
b=\frac{2\times 4b-3}{4b}
Since \frac{2\times 4b}{4b} and \frac{3}{4b} have the same denominator, subtract them by subtracting their numerators.
b=\frac{8b-3}{4b}
Do the multiplications in 2\times 4b-3.
b-\frac{8b-3}{4b}=0
Subtract \frac{8b-3}{4b} from both sides.
\frac{b\times 4b}{4b}-\frac{8b-3}{4b}=0
To add or subtract expressions, expand them to make their denominators the same. Multiply b times \frac{4b}{4b}.
\frac{b\times 4b-\left(8b-3\right)}{4b}=0
Since \frac{b\times 4b}{4b} and \frac{8b-3}{4b} have the same denominator, subtract them by subtracting their numerators.
\frac{4b^{2}-8b+3}{4b}=0
Do the multiplications in b\times 4b-\left(8b-3\right).
4b^{2}-8b+3=0
Variable b cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by 4b.
a+b=-8 ab=4\times 3=12
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as 4b^{2}+ab+bb+3. To find a and b, set up a system to be solved.
-1,-12 -2,-6 -3,-4
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 12.
-1-12=-13 -2-6=-8 -3-4=-7
Calculate the sum for each pair.
a=-6 b=-2
The solution is the pair that gives sum -8.
\left(4b^{2}-6b\right)+\left(-2b+3\right)
Rewrite 4b^{2}-8b+3 as \left(4b^{2}-6b\right)+\left(-2b+3\right).
2b\left(2b-3\right)-\left(2b-3\right)
Factor out 2b in the first and -1 in the second group.
\left(2b-3\right)\left(2b-1\right)
Factor out common term 2b-3 by using distributive property.
b=\frac{3}{2} b=\frac{1}{2}
To find equation solutions, solve 2b-3=0 and 2b-1=0.
b=\frac{2\times 4b}{4b}-\frac{3}{4b}
To add or subtract expressions, expand them to make their denominators the same. Multiply 2 times \frac{4b}{4b}.
b=\frac{2\times 4b-3}{4b}
Since \frac{2\times 4b}{4b} and \frac{3}{4b} have the same denominator, subtract them by subtracting their numerators.
b=\frac{8b-3}{4b}
Do the multiplications in 2\times 4b-3.
b-\frac{8b-3}{4b}=0
Subtract \frac{8b-3}{4b} from both sides.
\frac{b\times 4b}{4b}-\frac{8b-3}{4b}=0
To add or subtract expressions, expand them to make their denominators the same. Multiply b times \frac{4b}{4b}.
\frac{b\times 4b-\left(8b-3\right)}{4b}=0
Since \frac{b\times 4b}{4b} and \frac{8b-3}{4b} have the same denominator, subtract them by subtracting their numerators.
\frac{4b^{2}-8b+3}{4b}=0
Do the multiplications in b\times 4b-\left(8b-3\right).
4b^{2}-8b+3=0
Variable b cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by 4b.
b=\frac{-\left(-8\right)±\sqrt{\left(-8\right)^{2}-4\times 4\times 3}}{2\times 4}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 4 for a, -8 for b, and 3 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
b=\frac{-\left(-8\right)±\sqrt{64-4\times 4\times 3}}{2\times 4}
Square -8.
b=\frac{-\left(-8\right)±\sqrt{64-16\times 3}}{2\times 4}
Multiply -4 times 4.
b=\frac{-\left(-8\right)±\sqrt{64-48}}{2\times 4}
Multiply -16 times 3.
b=\frac{-\left(-8\right)±\sqrt{16}}{2\times 4}
Add 64 to -48.
b=\frac{-\left(-8\right)±4}{2\times 4}
Take the square root of 16.
b=\frac{8±4}{2\times 4}
The opposite of -8 is 8.
b=\frac{8±4}{8}
Multiply 2 times 4.
b=\frac{12}{8}
Now solve the equation b=\frac{8±4}{8} when ± is plus. Add 8 to 4.
b=\frac{3}{2}
Reduce the fraction \frac{12}{8} to lowest terms by extracting and canceling out 4.
b=\frac{4}{8}
Now solve the equation b=\frac{8±4}{8} when ± is minus. Subtract 4 from 8.
b=\frac{1}{2}
Reduce the fraction \frac{4}{8} to lowest terms by extracting and canceling out 4.
b=\frac{3}{2} b=\frac{1}{2}
The equation is now solved.
b=\frac{2\times 4b}{4b}-\frac{3}{4b}
To add or subtract expressions, expand them to make their denominators the same. Multiply 2 times \frac{4b}{4b}.
b=\frac{2\times 4b-3}{4b}
Since \frac{2\times 4b}{4b} and \frac{3}{4b} have the same denominator, subtract them by subtracting their numerators.
b=\frac{8b-3}{4b}
Do the multiplications in 2\times 4b-3.
b-\frac{8b-3}{4b}=0
Subtract \frac{8b-3}{4b} from both sides.
\frac{b\times 4b}{4b}-\frac{8b-3}{4b}=0
To add or subtract expressions, expand them to make their denominators the same. Multiply b times \frac{4b}{4b}.
\frac{b\times 4b-\left(8b-3\right)}{4b}=0
Since \frac{b\times 4b}{4b} and \frac{8b-3}{4b} have the same denominator, subtract them by subtracting their numerators.
\frac{4b^{2}-8b+3}{4b}=0
Do the multiplications in b\times 4b-\left(8b-3\right).
4b^{2}-8b+3=0
Variable b cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by 4b.
4b^{2}-8b=-3
Subtract 3 from both sides. Anything subtracted from zero gives its negation.
\frac{4b^{2}-8b}{4}=-\frac{3}{4}
Divide both sides by 4.
b^{2}+\left(-\frac{8}{4}\right)b=-\frac{3}{4}
Dividing by 4 undoes the multiplication by 4.
b^{2}-2b=-\frac{3}{4}
Divide -8 by 4.
b^{2}-2b+1=-\frac{3}{4}+1
Divide -2, the coefficient of the x term, by 2 to get -1. Then add the square of -1 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
b^{2}-2b+1=\frac{1}{4}
Add -\frac{3}{4} to 1.
\left(b-1\right)^{2}=\frac{1}{4}
Factor b^{2}-2b+1. 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(b-1\right)^{2}}=\sqrt{\frac{1}{4}}
Take the square root of both sides of the equation.
b-1=\frac{1}{2} b-1=-\frac{1}{2}
Simplify.
b=\frac{3}{2} b=\frac{1}{2}
Add 1 to both sides of the equation.
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}