you would get two values. 4k*2k^2=8k^3 because you multiply the #'s in front of the variables and because you have like terms you would add the exponents-k^2+k^1=k^3(any variable without a visible exponent has an exponent of 1 -ex. k=k^1) Next, -7k *3*4k =-21k or if it's -7k+3 you would get -28k^2 +12k, so depending on what it is(sorry I was confused about how the problem was written) you'll either end up with 8k^3-81k^2 or 8k^3-28k^2+12k
(always place unlike terms in order from greatest to least with exponents)