13. xy= x times by y 14. 7/t-4= 7 divided by t take away 4 15. 22+t 2= 22 add t squared 16. 51-x= 51 take away x 17. x-y^2= x take away y squared 18. 36/12+12= 36 divided by 12 add 12 19. ab-16= a times by b take away 16
If this is what it means , I hope this helped ! :)