Joni’s hair is 13 inches long and grows at an average rate of ⅔ in per month. Her friend Kate’s hair is 16 inches long and grows at an average rate of ½ in per month. How many months will pass before the two friends have the same hair length?

Solution:

Let "x" be the number of months

Joni’s hair is 13 inches long and grows at an average rate of ⅔ in per month

Her friend Kate’s hair is 16 inches long and grows at an average rate of ½ in per month

For two friends to have the same hair length, eqn 1 must be equal to eqn 2

Thus 18 months will pass before the two friends have the same hair length

first option

a function is a relation in which an input is paired with exactly one output.

so, let's find the right answer.

in our first option, our inputs are january, february, and march. the outputs are 30, 28, and 25. each input has it's own output. this is correct!

our second option we know is incorrect, because ms. valverade has two outputs, dogs and cats. this is not a function.

our third option is incorrect as well. the yellow square has two ouputs, the square and the triangle.

lastly, in our fourth option, we see the number 7 two times with a different output. therefore, this is not a function.

remember: each input must be paired with only one output!

option a is correct.

step-by-step explanation:

scale factor: it is used to find proportional measurements.

proportions means having the same ratio.

scale factor is the ratio of the model measurement to the actual measurement in a simplest form.

or we can say that the ratio of any two corresponding lengths in two similar geometric figures

if the scale factor is more than 1, then it is an enlargement,

if the scale factor less than 1, then it is a reduction.

given the two geometric figure:

by definition of proportions, we have