Find an unknown numerator or denominator in a fraction using our simple calculator. Enter an “x” for the unknown value and the calculator will solve for x.
Start by cross-multiplying the fractions
Simplify the expression
Multiply the known values
Divide both sides by 2 to get x
Additional Fraction Tools
Solving Fractions in Algebraic Equations
You can solve for x in an algebra equation that is a fraction by following a few simple steps.
Cross Multiply the Fraction
The first step to solving for the unknown numerator or denominator in a fraction is to cross-multiply the numerators and denominators. This will create a new equation that is not a fraction and is easier to solve. For example, the equation x/3 = 3/4 can be cross-multiplied to create the equation (4 × x) = ( 3 × 3). This can be simplified a bit as 4x = 9.
Divide to Get x By Itself
The next step is to get x by itself by dividing the number in front of the x. For example, the equation 4x = 9 can be re-written as 4x/4 = 9/4, which is the same as x = 9/4.
Reduce the Fraction
The final step is to reduce the fraction by finding the greatest common factor of the numerator and the denominator. In the example above, 9/4 cannot be simplified, but it can be turned into a mixed fraction. to do this, take 9 ÷ 4 = 2 R1. The whole number is 2 and the remainder is 1, thus 9/4 = 2 1/4. You can also use our reduce fraction calculator to reduce your fraction.