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Simplify the following by using (a+b)(a-...

Simplify the following by using `(a+b)(a-b)=a^2-b^2`
(i) `68 xx 72`
(ii) `101 xx 99`
(iii) `67 xx 73`
(iv) `128^2-77^2`

Text Solution

Verified by Experts

Given:
`(i)68 xx 72`
Using `(a+b)(a-b)=a^2-b^2`
`=>(70-2)(70+2)`
`=>(70)^2-(2)^2`
`=>4900-4`
`=>4896`
`(ii) 101 xx 99`
...
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