Question

№152. Выполните  действие:
1)(k+t)(k-t)
2)(n+1)(n-1)
3)(7m+3n)(7m-3n)
4)(2m+3)(2m-3)

Answer 1

1)(k+t)(k-t)=k^2-t^2
2)(n+1)(n-1)=n^2-1
3)(7m+3n)(7m-3n)=49m^2-9n^2
4)(2m+3)(2m-3)=4m^2-9