Help me? Algebra 2?

Any angle coterminal with 7π/4 can be expressed as 7π/4 + 2πx, with x being an integer. You can also observe the quadrant where each angle terminates as a guide to eliminate wrong choices. On that subject, 7π/4 is in quadrant 4.

-7π/4 -- No. This is in quadrant 1 (coterminal with π/4).

-π/4 -- Yes. Let x = -1; 7π/4 - 2π = -π/4, so this is coterminal.

3π/4 -- No. This is in quadrant 2.

9π/4 -- No. This is in quadrant 1 (coterminal with π/4).

15π/4 -- Yes. Let x = 1; 7π/4 + 2π = 15π/4, so this is coterminal.

2π -- No. This forms part of the x-axis and is not in a quadrant.

Answers #2 and #5 are the right choices.

Any angle co-terminal with 7pi/4 must be f the form 7pi/4 (+/-) (2n)pi. Only 2 such

angles are presented in the list : -pi/4 and 15pi/4.

its -pi/4 and 15pi/4 because those are minus 2pi and plus 2pi of 7pi/4 respectively

To be coterminal with {7(Pi)/4} the angle must be {n(2)(Pi)} + {7(Pi)/4} where n is an interger, positive or negative.  You should be able to figure it from there