Evaluate
9\sqrt{5}-21\approx -0.875388203
Factor
3 {(3 \sqrt{5} - 7)} = -0.875388203
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3\sqrt{3}\sqrt{15}-7\left(\sqrt{3}\right)^{2}
Use the distributive property to multiply \sqrt{3} by 3\sqrt{15}-7\sqrt{3}.
3\sqrt{3}\sqrt{3}\sqrt{5}-7\left(\sqrt{3}\right)^{2}
Factor 15=3\times 5. Rewrite the square root of the product \sqrt{3\times 5} as the product of square roots \sqrt{3}\sqrt{5}.
3\times 3\sqrt{5}-7\left(\sqrt{3}\right)^{2}
Multiply \sqrt{3} and \sqrt{3} to get 3.
9\sqrt{5}-7\left(\sqrt{3}\right)^{2}
Multiply 3 and 3 to get 9.
9\sqrt{5}-7\times 3
The square of \sqrt{3} is 3.
9\sqrt{5}-21
Multiply -7 and 3 to get -21.
Examples
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y = 3x + 4
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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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