Maths----- Linear Equations in one Unknown

1. -6{6n-(5n+1)} = 3n+1
-36n+30n+6 = 3n+1
6-1 = 3n+36n-30n
5 = 9n
n = 5/9

2. 係咪 2/3 - (2x)/2 = -1/12 ??
2/3 - x = -1/12
x = 2/3 + 1/12
x = [2(4) + 1 ]/12
x = 9/12
x = 3/4

3. 係咪 3(b-5)/2 = 2b/3 ??
3[3(b-5)] = 2(2b)
9b-15 = 4b
9b-4b = 15
5b = 15
b = 15/5
b = 3

我只能看到第1題問題，所以我就答第1題：

-6{6n-(5n+1)}=3n+1
-6(-30n^2 -6n) = 3n+1
180n^2 +36n = 3n+1
180n^2 +33n -1 = 0

n^2 = n的平方