Solve for x
x = \frac{21}{5} = 4\frac{1}{5} = 4.2
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9x+7-4x=28
Subtract 4x from both sides.
5x+7=28
Combine 9x and -4x to get 5x.
5x=28-7
Subtract 7 from both sides.
5x=21
Subtract 7 from 28 to get 21.
x=\frac{21}{5}
Divide both sides by 5.
Examples
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{ x } ^ { 2 } - 4 x - 5 = 0
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Linear equation
y = 3x + 4
Arithmetic
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Matrix
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Simultaneous equation
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Differentiation
\frac { d } { d x } \frac { ( 3 x ^ { 2 } - 2 ) } { ( x - 5 ) }
Integration
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Limits
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