1) 5n+1 и -6-3n-4
5n+1+(-6-3n-4)=5n+1-6-3n-4=2n-9
5n+1-(-6-3n-4)=5n+1+6+3n+4=8n+11
2) 1.3n - 6 и -3n-8n
1.3n-6+(-3n-8n)=1.3n-6-3n-8n=-9.7n-6
1.3n-6-(-3n-8n)=1.3n-6+3n+8n=12.3n-6
3) -16 +21 и-3.5+n-2n
-16+21+(-3.5+n-2n)=-16+25-3.5+n-2n=5.5-n
-16+25-(-3.5+n-2n)=-16+25+3.5-n+2n=12.5+n
4)-8+16.2 и a-3a+1.5a
-8+16.2+(a-3a+1.5a)=-8+16.2+a-3a+1.5a=8.2-0.5a
-8+16.2-(a-3a+1.5a)=-8+16.2-a+3a-1.5a=8.2+0.5a