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NCERT Class XI Mathematics - Binomial Theorem - Solutions

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Question : 18 of 36
Marks: +1, -0
(x2yx)12(x^2 - yx)^{12} , x ≠ 0
Solution:  
We have given (x2yx)12(x^2 - yx)^{12} = (x2+(y))12(x^2 + (-y))^{12} , x ≠ 0
∴ The general term is Tr+1T_{r+1} = 12Cr(x2)12r(yx)r{}^{12}C_r (x^2)^{12-r} (-yx)^r
= 12Crx242r(1)ryrxr\,{}^{12}C_r x^{24-2r} (-1)^r y^r x^r = (1)r6Crx242r+ryr(-1)^r \,{}^{6}C_r x^{24-2r+r} y^r = (1)r12Crx24ryr(-1)^r \,{}^{12}C_r x^{24-r} y^r
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