4 cookies cost $7. At this rate, how much will 9 cookies cost?

$15.75

you multiply the 4 cookies by 2 to get 8 ($14), then, you divide 7 by 4 to get the cost of one cookie ($1.75). add that to 14, and thus, your answer.

Step-by-step explanation:

Given the following fraction

½, ⅛ and ⅝

Notice that both the ⅛ and ⅝ have the same denominator, so let make ½, also have a denominator of 8, by multiplying both the numerator and denominator by 4

So we are going to have,

1×4/2×4=4/8

Note, this doesn't change the value of the original number.

Then, the three fractions becomes

4/8, ⅛ and ⅝

Now, using the numerator to know which number is bigger we notice that numerator 5 is greater numerator 4, and also numerator 4 is greater than numerator 1

Then, conclusion

⅝>4/8>⅛

Then, ⅝ is greater than 4/8 and 4/8 is greater than ⅛ and this implies that ⅝ is greater than ⅛

The three comparison are

1. ⅝ > 4/8

2. 4/8 > ⅛

3. ⅝ > ⅛