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Anuradha Chikane asked in Math

10. Factorise [Hint:- Use suitable identity]:-

a )   x 4 - 100                                                           c )   y 4 - 81 b )   160 4 - 81 b 4                                               d )   49 x 2 - 121 y 2

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Neha Sethi answered this

Dear student
a) x4-100=x22-102=x2-10x2+10    using a2-b2=a+ba-b=x2+10x2-102=x2+10x-10x+10     using a2-b2=a+ba-bc) y4-81=y22-92=y2-9y2+9    using a2-b2=a+ba-b=y2+9y2-32=  y2+9y-3y+3         using a2-b2=a+ba-bd) 49x2-121y2=7x2-11y2=7x-11y7x+11y    using a2-b2=a+ba-b
Similarly try other.
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