Some algebra confusion.10 points to the best answer?

Choose the correct answer.

Elena has bought 320 tropical fish for a museum display. She bought 7 times as many triggerfish as parrotfish. How many of each type of fish did she buy? Write a system of equations to model the problem if x represents the number of parrotfish Elena bought, and y represents the number of triggerfish she bought.
x + 7y = 320
y = 7x

x + y = 7
y = 320x

x + y = 320
y = 7x

x- y = 320
y = 7x

2. For each of the following questions, choose the correct answer.

Elena has bought 320 tropical fish for a museum display. She bought 7 times as many triggerfish as parrotfish. How many of each type of fish did she buy?

280 parrotfish, 40 triggerfish

20 parrotfish, 140 triggerfish

120 parrotfish, 200 triggerfish

40 parrotfish, 280 triggerfish

3. For each of the following questions, choose the correct answer.

Anita and Joelle bowl together and their combined total score for one game was 425 points. Anita’s score was 40 less than twice Joelle’s. What were their scores? Write a system of equations to model the problem if x represents Joelle’s score, and y represents Anita’s score.

x + y = 425
y = 2x – 40

x + y = 425
y = 2x + 40

x – y = 425
y = 2x – 40

x + y = 40
y = 2x – 425