Solution: 1 Let the analytical formula of this line be: y = 3x+b.

Because it passes a (-1, 2).

So 2=-3+b b=5.

So: y=3x+5.

Intersection point with X axis (-5/3,0) and intersection point with Y axis (0,5)

Area =5×5/3÷2=25/6

2.y=-5/2x=4 is a plus sign or a minus sign, but it doesn't matter.

Let y =-5x/2+b.

Because after (-2,3)

3=5+b b=-2

y=-5x/2-2

Judge that A:-5/2× 4-2 =- 12 ≠ 9 does not exist.

Judge B:-5/2× 2-2 =-7 inches.

3. Find the intersection:

y=-2/(-2)= 1

Intersection coordinates (-2, 1)

Jean: y=-5x+b

1 =-5 *(2)+b

b=-9

∴y=-5x-9