Q1) A route up a mountain is 20 km long john followed this routeat the average s
ID: 3091290 • Letter: Q
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Q1) A route up a mountain is 20 km long john followed this routeat the average speed of x km/h a)Write down an expression in trems of x for a number of hourshe tooks to walk up the mountain b)he came down the mountain by a different route the lenght ofthis route was 25 km his average speed coming down the mountain was2 m per hour greater then his average speed going up the mountainwrite down an expression in terms of x for the number of hours hetook to walk down c)if took john one and half hours less to come downthen to go up write down an equation in x and show that itsimplifies to 3x^2+16x-80-0 Q1) A route up a mountain is 20 km long john followed this routeat the average speed of x km/h a)Write down an expression in trems of x for a number of hourshe tooks to walk up the mountain b)he came down the mountain by a different route the lenght ofthis route was 25 km his average speed coming down the mountain was2 m per hour greater then his average speed going up the mountainwrite down an expression in terms of x for the number of hours hetook to walk down c)if took john one and half hours less to come downthen to go up write down an equation in x and show that itsimplifies to 3x^2+16x-80-0Explanation / Answer
Q1) A route up a mountain is 20 km long john followed this routeat the average speed of x km/h a)Write down an expression in trems of x for a number of hourshe tooks to walk up the mountainy=20/x
b)he came down the mountain by a different route the lenght ofthis route was 25 km his average speed coming down the mountain was2 m per hour greater then his average speed going up the mountainwrite down an expression in terms of x for the number of hours hetook to walk down
z=25/(x+2)
c)if took john one and half hours less to come downthen to go up write down an equation in x and show that itsimplifies to 3x^2+16x-80-0
25/(x+2)+1.5=20/x
multiple by x+2
25+1.5(x+2)=(20/x)(x+2)
25+1.5x+3=(20x+40)/x
multiply by x
25x+1.5x2+3x=20x+40
combine terms
28x+1.5x2=20x+40
subtract 20x +40 from each side
8x+1.5x2-40=0
multiply by 2
16x+3x2-80=0
put in normal form
3x2+16x-80=0
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