Setting up Equations

Question

Set up an equation that describes the relationship between the two variables in each of the following case.

a. A person invests $10 000, x dollars at 10% and the rest at 8%. Write an equation for the interest/earned on the $10 000.

b. If you have C cents consisting of n nickels and d dimes, what is the equation relating C, n, and d?

c. A person is h inches tall and another person is i inches tall. If the difference in their heights is 10 inches and the sum of their heights is 110 inches, what system of equations represents these facts?

Answer 1

1) 0.10Z + 0.08(10,000-Z) = I where Z is the amount of money invested at the rate of 10%

and I is the interest earned.

The problem should state simple or compounded interest. The assumption of simple interest is made here.

2) 5n + 10d = C

3) h - i = 10

h + i = 110