### Home > CALC > Chapter Ch12 > Lesson 12.2.1 > Problem 12-73

12-73.

Only consider orders ≥ 80 chairs.

The cost of the chairs before the discount is 145*x* for *x* chairs.

The discount for 81 chairs is 0.50(1)(81).

The discount on 82 chairs is 0.50(2)(82).

The discount on 83 chairs is 0.50(3)(83).

...

The discount amount is 0.50(*x* – 80)*x*.

Write an equation for the total cost, including the discount.

Then maximize the equation.

Remember, *x* = # of chairs and the problem asks for the cost.