Find the length of KNJ explain your answer

Negative 5 1/12 + negative 4 1/4 + 6 3/4

For each sentence below, find the value of x that makes each sentence true. (515) 5 = 25* x= (813)2 = 4* x=

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?