=(a? +2ab+b? )+(2a? +ab-2ab-b? )-9
= 3a? +ab -9
2、x? +3x=8
x? +3x-8=0
Δ=3? - 4× 1×(-8) = 4 1
∴x = (-3 √4 1)/2
3、x^m = 3 x^n = 1/3
Multiplication: x (m+n) = 1
∴m+n=0
The conditions for calculating m and n are not sufficient.