Find the squares of the following numbers using the identity `(a+b)^2=a^2+2a b+b^2` (I)509 (ii) 211 (iii) 625

Explanation

(1)`(509)^2=(500+9)^2`
`=(500)^2+(9)^2+2xx500xx9`
`=250000+81+9000`
`=259081`
(ii)`211^2=(200+11)^2`
`=(200)^2+(11)^2+2xx200xx11`
`=40000+121+4400`
`=44521`
(iii)`(625)^2=(600+25)^2`
`=(600)^2+(25)^2+2xx600xx25`
`=360000+625+30000`
`=390625`