Answer:
A.) 65x + 35X + 50 = 250
65x = cost of concrete per cubic yard, x is yd³
35X = cost of pouring/finishing concrete per cubic yard, X is yd³
50 = delivery cost
250 = the money you have
B.) 400 + 15n = 505
15n = amount of money you deposite per week, n is # of week
400 = some money in account after n week passed
505 = initial money in bank
C.) 1.1X - 10 = 55
55 = total cost of clothes
1.1X = tax rate where X is the undiscounted clothe cost
10 = discount