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Question
Find the cube of the following binomials expression :
\[2x + \frac{3}{x}\]
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Solution
In the given problem, we have to find cube of the binomial expressions
Given `(2x + 3/x)^3`
We shall use the identity `(a+b)^3 = a^3+b^3 +3ab(a+b).`
Here `a = 2x,b = 3/x,`
By applying identity we get
`(2x + 3/x)^3 = (2x)^3 +(3/x)^3 + 3 (2x) (3/x) (2x+3/x)`
`= 2x xx 2x xx2x|+3/x xx3/x xx 3/x+18x/x (2x+3/x)`
`= 8x^3 +27/x^3 + (18x)/x (2x + 3/x)`
` = 8x^3 +27/x^3 + (18xx 2x) +(18 xx 3/x)`
`8^3+27/x^3 + 36x +54/x`
Hence cube of the binomial expression of `(2x + 3/x) 8^3+27/x^3 + 36x +54/x`
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