Janelle’s hair was 16.8 cm at the beginning of the school year. at the end of the year, the length of her hair had increased by 2.5%. how much did her hair grow during the year?

The hair grow at the end of year (17.22 cm - 16.8 cm) = 0.42 cm

Step-by-step explanation:

Given in the question as:

The height of hair of Janelle's at the beginning of school = 16.8 cm

The length of hair increased by 2.5%

Let the length of hair after increment = x

So, x = 16.8 cm + 2.5 % of 16.8 cm

Or, x = 16.8 cm × ( 1 + )

Or, x = 16.8 cm × (

∴  x = 17.22 cm

 Answer

the direct variation says that:

then the equation is of the form is given by:

            where k is the constant variation.

from the given table:

consider any value of x and m(x)=y

x = 2 and m(x)=y = 3

substitute these value in [1]; we have;

divide both sides by 2 we get;

⇒

check:

put x = -1 and m(x) = -1.5

substitute in the equation:

-1.5 = -1.5                   true

therefore, the function m(x) represents a direct variation

graph of this function as shown below: