a) Ta có : \(2^4\)= \(\left(2^2\right)^2\)= \(4^2\)>  \(3^2\)

=>  \(3^2\)< \(2^4\)

b) Ta có : \(\left(3+4\right)^2\)=  \(3^2\)+ \(24\)+\(4^2\)> \(3^2\)+ \(4^2\)

=>  \(3^2\)+  \(4^2\)<  \(\left(3+4\right)^2\)

c) Ta có : \(13^2-9^2\)=  \(\left(13-9\right)\left(13+9\right)\)= \(4\cdot22\)> \(4^2\)= \(\left(13-9\right)^2\)

=> \(13^2-9^2\)<     \(\left(13-9\right)^2\)

nhớ nha