Hey there!!
The total number of cents - 20
Cost for each pencil - 3 cents
Number of pencils bought - ' x '
y = number of pennies left
What is the domain ?
Show how y is dependent on x ..
Let's get this into an equation :
... The total cost for x pencils bought = 3x
... Number of pennies left = 20 - 3x
... y = number of pennies left
... y = 20 - 3x
Notice : If the x value changes, the y value changes too
... If x = 1 , then , y = 17; If x = 2 , then , y = 14
Hence, we could say y is dependent upon x
Domain = ?
... Remember - The total number of pennies = 20 ; hence, the total cost cannot go above 20 cents.
Hence, we will have to work with inequalities
The equation :
... 20 ≥ 3x
Divide 3 on both sides
20 / 3 ≥ x
x ≥ 6.667
Let's take this as 6
Hence , the domain will be :
D : { 1 , 2 , 3 , 4 , 5 , 6 }
Hope my answer helps!
