1) y=-4x+3 и y=-0,25x-0,75
y = y
-4x+3 = -0.25x - 0.75
-0.25x + 4x = 3 + 0.75
3.75x = 3.75
x = 1
y = -4*1 + 3 = -4 + 3 = -1
(1; -1) - точка пересечения прямых
2) y=-x+3 и y=2x+3
-x+3 = 2x + 3
2x + x = 3 - 3
3x = 0
x = 0
y = 3
(0; 3) - точка пересечения прямых
3) 2-5(0,2y-2x)=3 (3x+2)+2y
4(x-2y)-(2x+y)=2-2 (2x+y)
2 - y + 10x = 9x + 6 + 2y
4x - 8y - 2x - y = 2 - 4x - 2y
x = 4 + 3y
6x - 7y = 2
6(4 + 3y) - 7y = 2
24 + 18y - 7y = 2
11y = -22
y = -22/11
y = -2
x = 4 - 3*2 = 4 - 6 = -2
Ответ (-2; -2)