Yes, both equations you've given x, y values for are linear.
How do you find out if it's linear or not? Look at the x values. 1, 2, and 3 increase by 1 each time. Their respective y values (20, 15, 10) decrease by 5 each time. If the rate of change is constant like that, the equation is linear.
If you have points like (1, 1) (2, 8) (3, 27) etc, you see that the rate of change is not constant. Each x value goes up by 1, but the second given y value increased by 7 while the next y value increased by 19, so since the rates of change are different, this equation is not linear.
I hope this helps.
Yes, both equations you've given x, y values for are linear.
How do you find out if it's linear or not? Look at the x values. 1, 2, and 3 increase by 1 each time. Their respective y values (20, 15, 10) decrease by 5 each time. If the rate of change is constant like that, the equation is linear.
If you have points like (1, 1) (2, 8) (3, 27) etc, you see that the rate of change is not constant. Each x value goes up by 1, but the second given y value increased by 7 while the next y value increased by 19, so since the rates of change are different, this equation is not linear.
I hope this helps.
