Is 1225 a perfect square?How?

Asked by sangita | 16th Apr, 2017, 02:18: PM

Expert Answer:

begin mathsize 16px style If space last space digit space is space always space 25 space means space it space is space always space square space of space straight a space number space whose space last space digit space left parenthesis unit space place right parenthesis space is space 5.
As space 12 space we space can space write space it space as space 3 cross times 4. space
It space is space square space of space 35.

NOTE colon space
To space find space the space square space of space straight a space number space whose space unit space place space is space always space 5 space then space we space have space short space cut space to space find space it space as space follows colon
For space example comma space we space want space to space find space 45 squared.
First space we space can space see space that space last space digit space is space 5 space then space last space two space digit space of space straight a space square space of space the space number space is space 25.
After space that space we space have space 4 space number space on space tenth space place. space We space will space take space next space number space of space 4 space which space is space 5.
4 cross times 5 equals 20.
The space square space of space 45 space is space 2025.
end style

Answered by Sneha shidid | 17th Apr, 2017, 08:12: AM