SOLUTION: Felipe is driving to Milwaukee .suppose that the distance to his destination (in miles) is a linear function of his total driving time in (minutes) . Felipe has 67 miles to his des

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Question 1025051: Felipe is driving to Milwaukee .suppose that the distance to his destination (in miles) is a linear function of his total driving time in (minutes) . Felipe has 67 miles to his destination after 49 minutes of driving . He has 47.5 miles to his destination after 75 minutes of driving . How many miles will he have after 85 minutes of driving ?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
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Felipe is driving to Milwaukee .suppose that the distance to his destination (in miles) is a linear function of his total driving time in (minutes) .
Felipe has 67 miles to his destination after 49 minutes of driving .
He has 47.5 miles to his destination after 75 minutes of driving .
How many miles will he have after 85 minutes of driving ?
:
Use the slope formula: m = %28y2-y1%29%2F%28x2-x1%29, where
x1=49; y1=67
x2=75; y2=47.5
:
m = %2847.5-67%29%2F%2875-49%29 = %28-19.5%29%2F26 = -3%2F4 = -.75
:
Use the point/slope y - y1 = m(x - x1)
y - 67 = -.75(x - 49)
y - 67 = -.75x + 36.75
y = -.75x + 36.75 + 67
y = -.75x + 103.75
Looks like this
+graph%28+300%2C+200%2C+-20%2C+150%2C+-20%2C+150%2C+-.75x%2B103.75%29+
"How many miles will he have after 85 minutes of driving ?"
x = 85
y = -.75(85) + 103.75
y = -63.75 + 103.75
y = 40 mi from home after 85 min