Question

using identities evaluate - a) 1.05*9.5 .......answer it fast

Answer 1

Hi !

1.05 can be written as =   1 + 0.05
9.5 can be written as = (1 - 0.05) *10

hence,

1.05*9.5 
= {1 + 0.05}*{(1 - 0.05) }*10

{1 + 0.05}*{(1 - 0.05)} this can be written in the form of the identity (a-b)(a+b) = a² - b²

= { 1² - (0.05)²}*10

= { 1 - 0.0025}*10

= 0.9975 *10

= 9.975

The ans is 9.975
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Hope this helps you !