2xy+3ab-4xy-9ab
First you wanna find like terms
Like 2xy and -4xy they have the same letters
SO do 2xy-4xy and you should a negative number like -2xy make sure after you subtract you and the letters one the number
Now do 3ab and -9ab the same way i did it with the other like terms you subtract and should get -6ab so after you gotten both of thoss solved you should have the expression
-2xy-6ab
Hope this helped :)
