The first step here is finding the gradient. We do this by dividing the difference in y (vertical) by the difference in x (horizontal).
To find the difference, you simply take the original value of x or y from the final value (use the coordinates for this)
(0 - 23)/(-1 - 10) = (-23)/-11 = 2.1 (to 1dp)
We can then find the y intercept with the formula:
y - y_1 = m (x - x_1)
Where m is the gradient, y_1 is a y value substituted from one of the two coordinates and x_1 is an x value from one of the coordinates you were given (it can be from either of the two as long as it is from the same coordinate as your y one).
So, let's use the first coordinate, (10,23) as they are both positive (so it will be easier to calculate).
m=2.1 " "y_1 = 23 " " and " "x_1 = 10
When we substitute this in, we get:
y - 23 = 2.1 (x - 10)
y - 23 = 2.1x - 21
y = 2.1x + 2
So, your line equation is:
y = 2.1x + 2
Hope this helps; let me know if I can do anything else:)
