1. Substitute the coordinates of the intersection point and the coordinates of the error solution into two straight lines y=ax+b and y=cx+5, and the equations can be solved.

Solution: -2=3a+b can be obtained from the meaning of the question.

-2=3c+5

1/4=3a/4+b because c is wrongly copied, (3/4, 1) is not substituted for y=cx+5.

The solutions are a=- 1, b= 1 and c=-7/3.

Therefore, the analytical expressions of two straight lines are y=-x+ 1 and y=-7/3x+5, respectively.

2. the function value y increases with the increase of the independent variable x, then k > 0, then m+2 > 0, so m >-2.

3. because k < 0 and y decrease with the increase of x, it is known that x 1 =-3 < x2 = 0 < x3 = 2, so y 1 > y2 > y3.

4. From the meaning of the question, y=-x+m and y=mx-4 are solved simultaneously.

x=(m+4)/(m+ 1)，y=(m？ -4)/(m+ 1)

And the intersection point is on the negative semi-axis of the X axis,

So x < 0, y=0,

m？ -4=0，(m+4)(m+ 1)& lt； 0→-4