Answer:
3k2 - k + 5
just add all of the variables or minus all of the variables and if u can add the non-variable numbers but if a variable has exponent add it with the same type of variable exponent so in this case 3k squared doesn't get added to anything so it just stays 3k2 and -2k gets added to k which equals -k cause -2k is bigger than k and if the bigger number is negative in any equation stays negative. Then u just add all the numbers which would be 7+-2 which would equal five.
Hope this helped