Answer: 80,000
Step-by-step explanation: Start by plugging in 50,000 into the function for x. This gives you C(50,000)=0.8(50,000)+40,000. Next, multiply 0.8×50,000=40,000. This makes the function C(50,000)=40,000+40,000. Finally, just add 40,000+40,000=80,000. Therefore, C(50,000)=80,000.