Упростите вырожения
a+(2-a)=
9x-(8x-(1-2x))=
4ab-(3ab-(2ab-(ab+1)))=

а+(2-а)=а+2-а=29х-(8х-(1-2х))=9х-(8х-1+2х)=9х- (10х-1)=9х-10х+1=х+14ab-(3ab-(2ab-(ab-1)))=4ab-(3ab-(2ab-ab-1))=4ab-(3ab+ab+1)=4ab-4ab-1=-1