Can somebody help me with these 2. Will mark brainliest!

What is the name used to describe a graph where for some value of x, there exists 2 or more different values of y?

3x + 4y = 5 x- 3y = -7 solve by substitution

Money off coupons have been circulated to 300 households. only 2/5 of these were redeemed (used) in the local supermarket to get a free shampoo. what fraction of coupons were unused? (ps: write how you got the answer)