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How to multiply rational expressions?
pls help me...

How to multiply rational expressions? pls help me...-example-1

1 Answer

3 votes

Point :

A × B = B × A

Ex)


(1)/(2) * (3)/(4) = (3)/(4) * (1)/(2) = (3)/(2) * (1)/(4)

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a )


\frac{12 {a}^(2) }{25 {b}^(3) } * \frac{5b}{4 {a}^(4) } = \frac{12 {a}^(2) }{4 {a}^(4) } * \frac{5b}{25 {b}^(3) } = \\


\frac{4 {a}^(2) * 3 }{4 {a}^(2) * {a}^(2) } * \frac{5b}{5b * 5 {b}^(2) } = \\


\frac{3}{ {a}^(2) } * \frac{1}{5 {b}^(2) } = \frac{3}{5 {a}^(2) {b}^(2) } \\

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b )


\frac{ {x}^(2) - 2x - 15 }{ {x}^(2) - 9 } * \frac{ {x}^(2 ) - 6x + 9 }{4x - 12} = \\


((x - 5)(x + 3))/((x - 3)(x + 3)) * ((x - 3)(x - 3) )/(4(x - 3)) = \\


((x - 5))/((x - 3)) * ((x - 3))/(4) = \\


((x - 3)(x - 5))/((x - 3) \: \: \: * \: \: 4) = (x - 5)/(4) \\

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And we're done.....♥️♥️♥️♥️♥️

User Nuthatch
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