Write a system of equations to describe the situation below, solve using elimination, and fill in the blanks.To keep in shape, Julie exercises at a track near her home. She requires 62 minutes to do 4 laps running and 10 laps walking. In contrast, she requires 65 minutes to do 5 laps running and 10 laps walking. Assuming she maintains a consistent pace while running and while walking, how long does Julie take to complete a lap?Julie takes _____ minutes to run a lap and _____ minutes to walk a lap.
Q. Write a system of equations to describe the situation below, solve using elimination, and fill in the blanks.To keep in shape, Julie exercises at a track near her home. She requires 62 minutes to do 4 laps running and 10 laps walking. In contrast, she requires 65 minutes to do 5 laps running and 10 laps walking. Assuming she maintains a consistent pace while running and while walking, how long does Julie take to complete a lap?Julie takes _____ minutes to run a lap and _____ minutes to walk a lap.
Define variables: Let's define two variables: let r be the time in minutes it takes Julie to run a lap, and w be the time in minutes it takes Julie to walk a lap. We can then write two equations based on the information given:For the first scenario (4 laps running and 10 laps walking taking 62 minutes):4r+10w=62For the second scenario (5 laps running and 10 laps walking taking 65 minutes):5r+10w=65
Write equations: Now we will use the elimination method to solve the system of equations. To eliminate one of the variables, we can multiply the first equation by −5 and the second equation by 4, so that when we add the two equations, the terms with r will cancel out.Multiplying the first equation by −5:−5(4r+10w)=−5(62)−20r−50w=−310Multiplying the second equation by 4:4(5r+10w)=4(65)20r+40w=260
Elimination method: Next, we add the two resulting equations to eliminate r:(−20r−50w)+(20r+40w)=−310+260−20r+20r−50w+40w=−310+2600r−10w=−50Now we can solve for w by dividing both sides by −10:−10−10w=−10−50w=5Julie takes 5 minutes to walk a lap.
Add equations: Now that we have the value for w, we can substitute it back into one of the original equations to find r. We'll use the first equation:4r+10w=624r+10(5)=624r+50=62Subtract 50 from both sides to solve for r:4r=62−504r=12Divide both sides by 4:r0r1Julie takes r2 minutes to run a lap.
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