Question

Help on number 4 please the coordinates are $6.00 and 3 pound and the other is $9.00 and 6 pounds.

Answer 1

First, we need to draw both points on the plane along with the line that crosses them, as follows:

Then, let's check whether those rates are proportional.

`\begin{gathered} (6)/(3)=2 \\ (9)/(6)=(3)/(2)=1.5 \end{gathered}`

Then, each pound costs $2 and $1.5 in store B and C, respectively.

Therefore:

`\begin{gathered} \text{rate of B}=(2)/(1.5)\text{ rate of C} \\ \Rightarrow\text{rate of B=}(4)/(3)\text{ rate of C} \end{gathered}`

Then, both rates are proportional, and the constant that defines the proportion is 4/3.