a=2b-3a/5-b make be the subject
a4a^{4}a4 - 7 a3a^{3}a3 + 13 a2a^{2}a2 + 3 a1a^{1}a1 - 18 = 0
90+133=
a=2b-3a/5-b
1781*24
2-11+15
1758 multiply by 398
simplify (64/81)^(-3/4)
2.(4+33x+3.4(2-3x))=40
