Answer:
An equation in the slope-intercept form will be:
- y = 15x+210
Step-by-step explanation:
We know The slope-intercept form of the line equation
where
- m is the rate of change or slope
- b is the y-intercept
Let x represent the time in months
Let y represent the amount of money remaining in the account.
Given that every month Monica withdraws $15 from this account for her contact lenses
Thus, the rate of change or slope = m = 15
Given that after 3 months she has $255 left in her account.
So, we take the point (3, 255)
substituting m = 15, x = 3 and y = 255 in the slope-intercept form to determine the y-intercept
y = mx+b
255 = 15(3) + b
switch sides
15(3) + b = 255
45 + b = 255
b = 255 - 45
b = 210
Now, substituting m = 15 and b = 210 in the slope-intercept form of the line equation
y = mx+b
y = 15x+210
Therefore, an equation in the slope-intercept form will be:
- y = 15x+210