Basically to write the question in equation form would be
4k(2k^2 - 7k + 3)
You must multiply 4k with each number in the parentheses.
4k x 2k^2 = 8k^3
4k x -7k = -28k^2
4k x 3 = 12k
The answer is 8k^3 - 28k^2 + 12k
Don't forget, when multiplying exponents, you're adding them, which is why 4k x 2k^2 = 8k^3. I'm adding k^1 and k^2 which is k^3