1. linear equation
2. rearrange the equation so 4y = 12 - 3× and then divide both sides by 4 to get:
y = 3 - 3/4×
3. equation of a straight line / linear equation
4. gradient is + 3
5. not sure sorry
6. 3x = 12 - 4y. Divide each side by 3 to get:
x = 4 - 4/3y
7. use y = 3 - 3/4x by doing and x and y table. So when x = 1, y = 3 - 3/4 (1) (replace the x which the x value you've chosen). Then plot.
8. Make up any problem such as weather, food, etc.
Hope that helps !