There are 16 coins totaling $1.08. All 16 coins were pennies, nickels, and dimes. The number of dimes is equal to the sum of the number of pennies and the number of nickels. How many of each coin is there?

Let the number of nickels be x

Let the number of pennies be y

Let the number of dimes be z

Now z=x+y

FIrst equation:

z+x+y=16

Subsittue for z:

x+y+x+y=16

y=8-x (subsitution)

Hope this helps :)

Step-by-step explanation:

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: