answer of Q2 in Maths answer key (shift 2) by Careers360 is wrong ....it should be 5 instead of 4 .. in last 2nd step 2(n-1)(n-1+1)/2 =20
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Hello aspirant,
Sorry for the wrong answer issued earlier. The answer will be 5 instead of 4.
The question is:
{2(n-1)*(n+1-1)}/2= 20
The answer is done as follows-
=> (n-1)*(n-1+1)= 20
=> n(n-1)= 20
=> n^2-n-20= 0
=> n^2-5n+4n-20= 0
=> (n^2-5n)*(4n-20)= 0
=> n(n-5)*4(n-5)= 0
=> (n+4)*(n-5)= 0
=> n+4= 0 OR n-5= 0
=> n=5 (Ans)
Hope, it helps you.
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