Equations for lines..help!!

1)Write down an equation for the line through (2;-1) and (-3; 3)

2) Write down an equation for the line which contains the point (-2; 4) which is:
(a) perpendicular to the line y = 2x + 3.
(b) parallel to the line y = 2x + 3.

3)Write down the domain of the function
y = (square root of x) divided by (x - 1)(x -2)

through (2;-1) and (-3; 3)

slope = (3--1)/(-3-2) 4/-5 =-4/5

y=-4/5x+b

3=-4/5*-3 +b

3= 12/5 +b
b=15/5-12/5
b=3/5

y =-4/5x +3/5

2a perpendicular to the line y = 2x + 3.
y=-1/2x+3
4=-1/2*-2+b
b=3

y=-1/2x+3

b. y=2x+b
4=2*-2+b
8=b

y=2x+8

3.x can not equal 1 or zero as you would have a denominator of 0

The points should be written (2, -1) and (-3, 3), not (2; -1) and (-3; 3).

Determine the slope of the line.
slope = (-1 - 3)/(2 - -3) = -4/5

point-slope equation of line:
y + 1 = (-4/5)(x - 2)
:::::

1) y = -4/5x + 3/5

2) y = -1/2x + 3

y = 2x + 8