Consider that a linear equation in slope intercept form is given by:
y = mx + b
where m is the slope of the line and b is the y intercept.
use the following formula to calculate the slope m:
where (x1,y1) and (x2,y2) are two pair of values of the table.
For (x1,y1) = (1,10) and (x2,y2) = (2,20) you have:
Next, use the same formula for m but replacing only the values of (x1,y1), just as follow:
and solve for y:
Hence, the slope is m = 10 and the y-intercept is b = 0
Then, the linear equation is y = 10x