Determine if the systems in Exercises 19 and 20 are consistent. Do not completely solve the systems. 19 X1 + 3x3 = 2 X2 - 3x4 = 3 3x1 - 2x2 + 3x3 + 2x4 = 1 +7x4 = -5

Write an application problem similar to Example 4.14. Then translate to a system of equations and solve it.

Use the system of three equations in three variables to solve each problem. Work schedules A college student earns 198.50 per week working three part-time jobs. Half of his 30-hour work week is spent cooking hamburgers at a fast-food chain, earning 5.70 per hour. In addition, the student earns 6.30 per hour doing janitorial work. How many hours per week does the student work at each job

Write an application problem similar to Example5.37 using the ages of two of your friends or family members. Then translate to a system of equations and solve it.