An equation that shows the dependence of [tex]y[/tex] on [tex]x[/tex] is [tex]y=20-3x[/tex] and the domain of the function is [tex]x=[0,6], x \in N[/tex].
Total number of cents [tex]= 20[/tex].
She bought [tex]x[/tex] pencils for [tex]3[/tex] cents each.
Let [tex]y[/tex] equals the number of cents left.
So, [tex]3x+y=20[/tex].
[tex]y=20-3x[/tex]
Here [tex]y[/tex] must be positive
So, [tex]20-3x>0[/tex]
[tex]20>3x[/tex]
[tex]\frac{20}{3}>x[/tex]
Domain of a function is the set of values for which the function is defined.
So, [tex]x[/tex] can get values from [tex]0[/tex] to [tex]6[/tex].
Therefore, the domain is:
[tex]x=[0,6], x \in N[/tex].
Learn more about domain here:
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