Please help me answer please and please actually answer please

What is x and y (use substitution? ) 5x+3y=38 and y=3x+8?

State whether weight is a function of height for the six students and explain. a. yes, height is a function of weight because two students weigh 165 pounds but have different heights. b. no, height is not a function of weight because two students weigh 165 pounds but have different heights. c. yes, weight is a function of height because for each value of height there is one corresponding value of weight. d. no, weight is not a function of height because there is not enough data to determine a function.

Need on this one asap im almost done with this subject