Please give me some help

When only separate discreet points are graphed it is called?

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?

Travis and paula went to lunch.travis ordered a sandwich for $7.50 and paula ordered a burger for $5.25.after lunch,they left a 15% tip for the waiter.how many money did they spend altogether?