Answer:
44
Explanation
4c + d
this is an expression and since they provided c and d it is easy to solve
c = 9 and d = 8. You need to plug in c and d into the expression to solve the problem.
4(9) + (8)
4 times 9 is 36 so it leaves you with 36 + 8
36 + 8 = 44
I hope this helps but basically the concept is just plugging in the numbers in place of the variables. For future problems plug in the numbers given where the variables are.