Asap end of the year too much stuff to do plz or i cant go to my dads house for my b day plz and keep looking at all my questions that i ask

Which ordered pair (c,d) is a solution to the given system of linear equations- c+2d=13 -9c-4d=-15

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)

If wxyz is a square, which statements must be true?