Solve for x
x=0.8
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0.28=\frac{28}{80}x
Cancel out 50 on both sides.
0.28=\frac{7}{20}x
Reduce the fraction \frac{28}{80} to lowest terms by extracting and canceling out 4.
\frac{7}{20}x=0.28
Swap sides so that all variable terms are on the left hand side.
x=0.28\times \frac{20}{7}
Multiply both sides by \frac{20}{7}, the reciprocal of \frac{7}{20}.
x=\frac{7}{25}\times \frac{20}{7}
Convert decimal number 0.28 to fraction \frac{28}{100}. Reduce the fraction \frac{28}{100} to lowest terms by extracting and canceling out 4.
x=\frac{7\times 20}{25\times 7}
Multiply \frac{7}{25} times \frac{20}{7} by multiplying numerator times numerator and denominator times denominator.
x=\frac{20}{25}
Cancel out 7 in both numerator and denominator.
x=\frac{4}{5}
Reduce the fraction \frac{20}{25} to lowest terms by extracting and canceling out 5.
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}