1) - 5a +7b+6b-2a-9a-3= - 16a+13b-3
2) 5÷(-5/4)+180, 34+3,1= - 5×4/5+180,34+3,4= - 4+180,34+3,1=179,44
1) - 5a +7b+6b-2a-9a-3= - 16a+13b-3
2) 5÷(-5/4)+180, 34+3,1= - 5×4/5+180,34+3,4= - 4+180,34+3,1=179,44