Question

Find a linear function that gives the cost in dollars of buying

Answer 1

Given that two boxes of Pop tarts cost four dollars and four boxes of Pop tarts cost six dollars.

The linear function that gives the cost in dollars of buying Pop tarts can be obtained using the equation of a straight line with passing through points (2, 4) and (4, 6) as follows:

$\frac{y-y_1}{x-x_1} = \frac{y_2-y_1}{x_2-x_1} \\ \\ \Rightarrow\frac{y-4}{x-2} = \frac{6-4}{4-2} = \frac{2}{2} =1 \\ \\ \Rightarrow y-4=x-2 \\ \\ \Rightarrow y=x-2+4=x+2$

Therefore, the linear function that gives the cost in dollars of buying Pop tarts is y = x + 2.