The average cost of an item is defined as the total cost to produce it divided by the number of units produced. A shoe
company that pays $240,000 in rent and employee salaries per
year figures it also must pay $3.50 in materials per shoe set it
produces.
Write an equation that represents how many shoe sets the
company would need for the average cost to be $7.50.

Statements reasons 1. ab ? cd; ad ? bc 1. given 2. ac ? ac 2. reflexive property 3. ? adc ? ? cba 3. ? 4. ? dac ? ? bca; ? acd ? ? cab 4. cpctc 5. ? dac and ? bca are alt. int. ? s; ? acd and ? cab are alt. int. ? s 5. definition of alternate interior angles 6. ab ? cd; ad ? bc 6. converse of the alternate interior angles theorem 7. abcd is a parallelogram 7. definition of parallelogram what is the missing reason in step 3?