5（x＋1.1）＝27.5
x+1.1=27.5/5
x+1.1=5.2
x=5.2-1.1
x=4.1
18.2—2（x—4)＝6.4
2(x-4)=18.2-6.4
2(x-4)=11.8
x-4=5.9
x=4+5.9
x=9.9