Question

Please help on this one?

Answer 1

Since the x axis represents the number of pen bought and the y axis the number of notebook, the total cost will be 2x+3y, because each pen costs 2$ and each notebook 3$.

You want this quantity to be no more than 30, so you must ask

`2x+3y \leq 30`

which means that the shaded area must be under the graph of the line

`2x+3y = 30`

You can rewrite the equation as

`y = -(2x)/(3) + 10`

So, the y intercept is the point
`(0,10)`

So the answer must be either C or D.

To find the x intercept, set y=0:

`0 = -(2x)/(3) + 10 \iff (2x)/(3) = 10 \iff 2x = 30 \iff x = 15`

So, the correct answer is D.