Sue is selling tickets for the circus. On day one she sold 4 senior tickets and 2 children's tickets and made $80. On day two she sold 5 senior tickets and 7 children's tickets making $145. how much were each senior and child's tickets?

Jusin I.'s answer is correct. I would just suggest using the letters a (for adult) and c (for children) as the variable names. These will be a better reminder of what the variables mean. Here is the check that he recommends using these letters.