Is 0 the solution to each equation ?

4 (x + 2) = 10

Julius sold five times as many computers as sam sold last year. in total, they sold 78 computers. how many computers did julius sell?

Amountain climber starts a climb at an elevation of 453 feet above sea level at his first rest stop he has climbed 162 feet and by his second rest stop he has climbed another 207 feet its getting late in the day so the climber starts his way down if the climber desends 285 feet how much does he need to ascend or descend to return to the original starting point

Jonathan puts $400 in a bank account. each year the account earns 6% simple interest. how much interest will be earned in 5 years?