My friend tott bought some frenks for 4$ each and some jooghs for 2$ each. the total cost was about 40$. Altogether he bought 19 items. write a system of equations, in standard form, modeling the relationship between frenks (x) and jooghs (y) how many frenks and jooghs did tott buy?

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?