номер 792
Упростить выражение

-2/5(15а+1/2b)+1/5b=-2/5*15/1a-2/5*1/2b+1/5b=-6a-1/5b+1/5b=-6a
4 2/5(3/11-a)-1 1/5=22/5*3/11-4 2/5a-6/5=6/5-4 2/5a-6/5= - 4 2/5a
-1/9(3b-9)+1/3b= -1/9*3/1b+19*9/1+1/3b= -1/3b+1+1/3b=1
-2 3/8(4c+8/19)+9 1/2c= -19/8*4/1c-19/8*8/19+19/2c= -19/2c-1+19/2c= -1