Slope is 3, and (1,4) is on the line

The first step is since you know what the slope is, you can just plug that into the equation. We now have y=3x+b, b being the y intercept.
3 is equal to 3/1, and you can use that to find the Y intercept. Start at the point that they game you and go up 3 and over 1. But this makes you further away from the Y axis, so you want to do the opposite. Go down 3 and over 1.\
This makes you end up on the Y intercept at (0,1)
Making the equation y=3x+1

Hello!

Formular: y = mx + c
Where, m = slope

Given that m = 3,
Substitude 3 into m

y = 3x + c
Then add the coordinates (1, 4)
Where 1 being x and 4 being y

4 = 3(1) + c
Solve for C next

c = 1
Substitude m and c into the formular

y = 3x + 1
And it's done!

Use this same method for the rest of the questions :)