Question

both the question are same difference is that in the 1st Q there is + sign and in the second Q there is - sign ^_^
but after solving 1 st Q i got the right ans (ans is matching wid my book ans)
but in the 2 nd Q when i solved it with the same process ans is. not matching why
^_^??
irrelevant answers will be reported

Answer 1

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The mistake that you did in solving the second question is in 2nd step,where you have subtracted 2 ×a^2×b^2.

Why did we subtract a^2×b^2 and add 2 × a^2 × b^2 in 1st question ?

Here , in the solution you might have seen there is +a^2×b^2.

So,if we shall add 2×a^2×b^2 and subtract a^2×b^2 the result will be a^2×b^2 only.

But in the 2nd question you have subtracted 2×a^2×b^2 and a^2×b^2 that will give you the result as -3×a^2×b^2 not -a^2×b^2.

Here is your solution :

=a^6 +b^6

= ( a^2)^3 + ( b^2)^3

= ( a^2 +b^2)( a^4 + b^4 -a^2× b^2 ).

Answer 2

=a^6 +b^6

= ( a^2)^3 + ( b^2)^3

= ( a^2 +b^2)( a^4 + b^4 -a^2b^2 ).