Answer:
That's all you're doing is writing the equation for two lines and finding out where they intersect. The slope is how much the price is increasing or decreasing and the y-intercept is where the price is starting at.
x = number of hours
y = mx + b = 0.12(x + 3) + 15.21 {It's (x + 3) because we have to add the 3 hours between 9 and noon}
y = mx + b = -0.11x + 15.96 {The slope is negative because the price is decreasing}
Set them equal to each other
0.12(x+3) + 15.21 = -0.11x + 15.96
Now solve for x
0.12x + 0.36 + 15.21 = -0.11x + 15.96
0.12x + 15.57 = -0.11x + 15.96
0.12x + 0.11x = 15.96 - 15.57
0.23x = 0.39
x = 0.38 / 0.23 = 1.7 hours
Convert 0.7 into minutes
0.7 hours * (60 min / 1 hour) = 42 min
So the prices are the same 1 hour and 42 min after noon, which is 1:42 PM
Step-by-step explanation:
