sn9 =66°
|2x+5|<0.5
3(4x-7)=10(x+5)
27 5/9-18 7/9=
5(2x+4)=8(x-3)
3(a-5)=2(2a+9)
7(b-3)=2(b+12)
10(a-5)=6(a-3)
4(x+3)+m(x+3)