Answer: 4
Step-by-step explanation: Here we're asked to evaluate 5c + cd given that c = 1/5 and d = 15.
So all we have to do is plug our given values for c and d into the problem and simplify from there.
5c would be 5(1/5) + c which is 1/5 · d which is 15 so we have (1/5)(15).
So rewriting our problem we have 5(1/5) + (1/5)(15).
Simplifying from here, remember that our order of operations tells us we must first multiply 5(1/5) and (1/5)(15).
So multiplying 5(1/5), the 5 and 5 cross cancel
to 1 and 1 so we have 1 · 1 or 1.
Next we have (1/5)(15) which we can rewrite as
(1/5)(15/1) which is 15/5 or 3.
So we now have 1 + 3 which is 4.
