Respuesta :

Answer:

a. 5ab                  b. 11x+15y

Answer:

a. 5ab

b. 11x+5y

Step-by-step explanation:

12ab-7ab they have the same variables, so you can just subtract

19x+5y-8x just rearrange it to 19x-8x+5y and subtract 19x and 8x