Solve for x
x=\frac{784-y}{3}
Solve for y
y=784-3x
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3x+y=784
Square both sides of the equation.
3x+y-y=784-y
Subtract y from both sides of the equation.
3x=784-y
Subtracting y from itself leaves 0.
\frac{3x}{3}=\frac{784-y}{3}
Divide both sides by 3.
x=\frac{784-y}{3}
Dividing by 3 undoes the multiplication by 3.
y+3x=784
Square both sides of the equation.
y+3x-3x=784-3x
Subtract 3x from both sides of the equation.
y=784-3x
Subtracting 3x from itself leaves 0.
Examples
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{ x } ^ { 2 } - 4 x - 5 = 0
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4 \sin \theta \cos \theta = 2 \sin \theta
Linear equation
y = 3x + 4
Arithmetic
699 * 533
Matrix
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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
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