Mutating multiple columns in a data frame using dplyr

Question

I have the following data frame df:

  v1 v2 v3 v4
1  1  5  7  4
2  2  6 10  3

And I want to obtain the following data frame

Answer 1

Just use mutate as is with a comma to separate new columns mutate(df,"v1v3"=v1*v3,"v2v4"= v2*v4)