1. The solution equation: {x-2y = - 1; 3 (X-2) = 1-y {4x-3y = - 2; X / 4 + Y / 6 = 3 2. First simplify, then evaluate (x-1) (X-2) - 3x (x + 3) - (x-1) ^ 2, where x = 3 3. Calculation: (- 1 / 2) ^ 2 / (- 2) ^ 3 * (- 2) ^ 2

1. The solution equation: {x-2y = - 1; 3 (X-2) = 1-y {4x-3y = - 2; X / 4 + Y / 6 = 3 2. First simplify, then evaluate (x-1) (X-2) - 3x (x + 3) - (x-1) ^ 2, where x = 3 3. Calculation: (- 1 / 2) ^ 2 / (- 2) ^ 3 * (- 2) ^ 2

x-2y=-1 ①
3(x-2)=1-y ②
From (1), x = 2y-1 (3)
Substituting (3) into (2), we get
3(2y-3)=1-y
6y-9=1-y
7y=10
y=10/7
Substituting y = 10 / 7 into 3, we get
x=20/7-1=13/7
4x-3y=-2 ①
x/4+y/6=3 ②
That is, 3x + 2Y = 36
① 2 × 2, 2 × 3
8x-6y=-4 ④
9x+6y=108 ⑤
④ + 5, get
17x=104
x=104/17
Substituting x = 104 / 17 into 3, we get
y=150/17
(x-1)(x-2)-3x(x+3)-(x-1)^2
=x^2-3x+2-3x^2-9x-(x^2-2x+1)
=x^2-3x+2-3x^2-9x-x^2+2x-1
=-3x^2-10x+1
=-3×9-10×3+1
=-27-30+1
=-56
(-1/2)^2/(-2)^3×(-2)^2
=(1/4)/(-8)×4
=-1/32×4
=-1/8