Answer:
y = -1/5x + 5
Explanation:
Since this is written in slope-intercept form, you need to follow this form:
y = mx + b
(where m is the slope and b is the y-intercept)
To find the slope, you need to do (rise/run) or (change in y/change in x) with (5, 4) and (15, 2):
(4 - 2) / (5 - 15)
= 2 / -10
= -1/5
so m = -1/5
To find the y-intercept, you just need to plug one of the points into the equation with the slope:
y = -1/5x + b
= 4 = -1/5(5) + b
= 4 = -1 + b
= b = 5
so b = 5
Now, you put it all together:
y = -1/5x + 5