Q8 of 26 Page 8

Evaluate (98)5

The expression (98)5can be written as.

We know that,


(x + a)n = nC0 .(x)n(a)0 + nC1 .(x)n - 1(a)1 + nC2 .(x)n - 2(a)2 + … + nCn .(x)0(a)n


(100 - 2)5 = 5C0 1005.20 - 5C1 1004.21 + 5C2.1003.22 - 5C3 .1002.23 + 5C4 .1001.24 - 5C5.1000.25



= 10000000000 - 1000000000 + 40000000 - 800000 + 8000 - 32


= 9039207968


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