Question

On some interstate highways, the maximum speed a car may drive is 65 mph. A tractor-trailer may not drive more than 55 mph. The minimum speed for all vehicles is 45 mph.

Write an inequality to represent the allowable speed s for a car on an interstate highway.
a.
45 < s < 65
c.
45 < s < 65
b.
45 > s > 65
d.
45 < s > 65

Answer 1

would you agree that the allowable speed is greater than 45 and less than 65

Answer 2

?

Answer 3

sure

Answer 4

okay which one of those says that s is bigger than 45 and less than 65?

Answer 5

b

Answer 6

when we wrtie this symbol < it means the number next to the open side is bigger than the number next to the point

Answer 7

c and d have a _ under the < and >

Answer 8

if we write 45 > s which number is bigger 45 or s?

Answer 9

45

Answer 10

correct! so if 45 is greater than the allowable speed, then the allowable speed is less than 45! Is this true?

Answer 11

yea

Answer 12

just a second ago you told me the allowable speed was greater than 45...

Answer 13

which one is it?

Answer 14

65

Answer 15

when we are driving on this road should we be going faster than 45 or slower?

Answer 16

faster

Answer 17

yes! so s should be greater than 45

Answer 18

we write that like this 45 < s

Answer 19

notice how the bigger one gets the open side

Answer 20

should s be less than 65 or greater than 65?

Answer 21

45 < s < 65

Answer 22

that is correct.. now what about the bars

Answer 23

grater or equeal.

Answer 24

so the bars shoulsnt be there.

Answer 25

are cars allowed to travel exactly 65?

Answer 26

yes

Answer 27

so then s can equal 65!

Answer 28

so. 45<_ s <_ 65

Answer 29

Ding ding ding!!! thanks for stickin through it!

Answer 30

itll pay off i promise!

Answer 31

oh so the line under it would be you can drive in bewtween 45 and 65
instead of just those speeds.

Answer 32

nooo the line means you are allowed to travel 65 exactly or less

Answer 33

oh alright.

Answer 34

without the line you could go 64.9999999 or less but not 65

Answer 35

thanhks

Answer 36

allowaable speed is "less than or equal to" 65

Answer 37

no problem =)