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What is the height of the candle after 7 hours

What is the height of the candle after 7 hours-example-1
User Eborrallo
by
6.2k points

1 Answer

3 votes

Let

y -----> candle heigh in centimeters

x ----> burning time in hours

In this problem we have the ordered pairs

(5,22.5) and (17,16.5)

step 1

Find out the slope

m=(16.5-22.5)/(17-5)

m=-6/12

m=-1/2 -----> is negative because is a decreasing function

step 2

Find out the equation in slope-intercept form

y=mx+b

we have

m=-1/2

point (5,22.5)

substitute

22.5=-(1/2)(5)+b

solve for b

b=22.5+2.5

b=25

therefore

y=-(1/2)x+25

step 3

For x=7 hours

substitute in the equation

y=-(1/2)(7)+25

y=-3.5+25

y=21.5 cm

User Phani K
by
6.4k points
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