Bill had 30 teeth when he was 40, and 20 teeth when he was 60

Well that means between the ages of 40 and 60 Bill lost 10 teeth

Step-by-step explanation:

If Bill had 30 teeth when he was 40, and had 20 teeth when he was 60 that means between the ages of 40 and 60 he lost 10 teeth.

Being that 60 minus 40 (60-40=20) is 20, that means he lost 10 teeth in 20 years. Averaging out to loosing 1 tooth every 2 years.

Sorry I was not completely sure what the question was, so I answered it in the most mathematical way possible. Hope I helped a little :)

the answer

b. they are parallel and will never intersect.

walter needs to make at least 5 more cookies but no more than 40. 5 ≤ x ≤ 40

step-by-step explanation:

20 ≤ x + 15 ≤ 55

subtract 15 from all parts

20-15 ≤ x + 15-15 ≤ 55-15

5 ≤ x ≤ 40

this means how many more cookies he has to make

walter needs to make at least 5 more cookies, but no more than 40 cookies; 5 ≤ x ≤ 40