Where does the +8 com from?

You have to plug in x = 0 to calculate the y-intercept.

Where did you find this -3 ? Plug in the coordinates of the point and check if you get a true statement. In your case:2. Show that (2, 1) lies on the same line with the equation y=2x+3

I started with: 2 x 2 + -3x1 = -3

that means the point doesn't belong to the line.

Why do you use the x-value in the place of the y-variable? Your method is OK but you should have gotten:3. Parallel to 3x-4y=2 passing through (1, 2)

I did: 3x-4y =3 x 1 - 4 x 1

=3x-4y=-1

and therefore the equation of the parallel line is

If a straight line has the equation4. Perpendicular to 3x-4y = 2 passing through (1, 2)

then the perpendicular line has the equation

So you know now the LHS of the equation. Find the value of d using the same way as in #3

to a): Two lines are parallel if the slopes and are equal. ThusAbsolutely no idea how to do this.

5. Two lines have slopes k+2=-1. Find k given that:

a. The lines are parallel

b. The lines are perpendicular

I got:

a. k+2 = -1

b. -1/2k

...

to b) Two lines are perpendicular to each other if the slopes satisfy the equation

I'll leave the rest for you.