2x (y^2+3)-5 (3+y^2)

Mathematics

1 answer:

Irina18 [472]3 years ago

3 0

Use distributive property a(b + c) = ab + ac.

$2x(y^2+3)-5(3+y^2)=(2x)(y^2)+(2x)(3)+(-5)(3)+(-5)(y^2)\\\\=2xy^2+6x-15-5y^2$

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Why is it mathematically legal to multiply 2 √ 2 by √ 2 √ 2 in order to rationalize the denominator?

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or whatever * 1 = whatever
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now, try this in your calculator $\bf \cfrac{2}{\sqrt{2}}\cdot \cfrac{\sqrt{2}}{\sqrt{2}}\implies \cfrac{2\sqrt{2}}{\sqrt{2^2}}\implies \cfrac{2\sqrt{2}}{2}\implies \sqrt{2}\\\\
-----------------------------\\\\
\textit{check how much is }\cfrac{2}{\sqrt{2}}\textit{ in your calculator}
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\textit{then check how much is }\sqrt{2}\textit{ in it}$