Describe and correct the error a student made finding the intercepts of the graph of the line 4x-6y=12

Tom can paint the fence in 12 hours, but if he works together with a friend they can finish the job in 8 hours. how long would it take for his friend to paint this fence alone?

In a two-digit number the units' digit is 7 more than the tens' digit. the number with digits reversed is three times as large as the sum of the original number and the two digits. find the number.

Find the distance between c and d on the number line c=3 and d=11