Can someone explain how i'm supposed to determine whether each pair of ratios form a proportion?

Any greatly appreciated! you in advance. jody bought 20 shares of amazon at the close price of $121.00. she bought 20 more shares a year later at the price of $127.00. two years later she's sold all of her shares at the price of $133.00. her broker charges $50 for each transaction. after all of these transactions how much money did jody make? a.$65.00b.$5288.00c.$210.00d.$310.00

Consider the proof. given: segment ab is parallel to line de. prove: what is the missing statement in step 5?

What is the length of the segment, endpoints of which are intersections of parabolas y=x2? 11 4 x? 7 4 and y=? 7 8 x2+x+ 31 8 ?