3a- b+15a2 + 5a при а=-0,8, b= 16
5a-2 2-5a
15a^2 -6a-b+15a^2/5a-2 +5a/2-5a=30a^2-6a-b-5a/5a-2=30a^2-11a-b/5a-2=30*0,64+8,8-16/-4-2=19,2+8,8-16/-6=28-16/-6=12/-6=-2