Evaluate
\left(x-8\right)\left(x+21\right)
Expand
x^{2}+13x-168
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x^{2}+21x-8x-168
Apply the distributive property by multiplying each term of x-8 by each term of x+21.
x^{2}+13x-168
Combine 21x and -8x to get 13x.
x^{2}+21x-8x-168
Apply the distributive property by multiplying each term of x-8 by each term of x+21.
x^{2}+13x-168
Combine 21x and -8x to get 13x.
Examples
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{ x } ^ { 2 } - 4 x - 5 = 0
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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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