Solve for x:
Verify by direct substitution that the given power series is a solution of the indicated differential equation.
A student bought a calculator and a textbook for a course in algebra. He told his friend that the total cost was $145(without tax) and that the calculator cost $20 more than four times the cost of the textbook. What was the cost of each item? Let
The corresponding modeling system is
Solve the system by using the method of substitution and enter the ordered pair.