1)а-4а+11+9-2а=-5а+20=20-5а
20-5a=20-5a
2)18b-24-15b+55+2=3b+33
3b+33=3b+33
1) a-(4a-11) +(9-2a) =20-5a
a-4a+11 + 9-2a =20-5a
a-4a-2a+5a=20-11-9
-7a=0
a=0÷-7
a=0
2) 6(3b-4) -5(3b-11) +2=3b+33
18b-24-15b+55+2=3b+33
18b-15b-3b=33+24-55-2
0b=0
