Aparticipant in a 21-mile walkathon walks at a steady rate of 3 per hours. he thinks, "the relationship between the number of miles left to walk and the number of hours i already walked can be represented by a line with slope -3." do you agree with his claim? explain your reasoning.

Yes. I agree with his claim because the equation relating the miles left to walk and the number of miles left to walk is :

Step-by-step explanation:

Given :

Let the number of miles walked be ;

∴,

The number of miles '' left to walk will be :

Thus the time '' for which he walked :

:

∴

From these equations , we get :

Thus , when we compare this with ,

Thus this is an equation of a Line with slope -3.

answer:   n ≤ -3 or n < -5

step-by-step explanation:

-5 + 2n ≥ -11

+5             +5

2n ≥ -6

2/2 ≤ -6/2

n ≤ -3

-6 - 10n > 44

+6           +6

-10n > 50

-10/-10 50/-10

n < -5

d. bc = 12 and ef = 16

step-by-step explanation:

we are given that δabc : δdef such that .

also, it is given that

so, from the options, we need that .

a.

b.

c.  

d.

as, we can see that only option d gives the same ratio as i.e. .

hence, the possible lengths are bc = 12 and ef = 16.