Question

Suppose that the equation v = 1,425g represents the price to purchase g ounces of gold from Company M. The table below shows the price to purchase different amounts of gold from Company N.

Which statement is true?
A. Company M sells gold for a lower price than Company N.
B. Company M sells gold for the same price as Company N.
C. Company N sells gold for a lower price than company M.

Answer 1

To see the rate at what each company sells their gold, we will need to identify the unit rates (the price per “g” of gold) for each company.

Remember that we have a basic linear equation in the form y=mx+b, where m=slope or rate of change. So, in company N’s equation: v=1,425g, the slope or rate of change is 1,425. This means the line rises 1,425 per every “g” of gold, so we can infer that company N sells gold at a rate of $1,425/g.

So, we know the unit rate for Company N: $1,425/g.

Now, we will follow the same process for company M as we did for company N. However, we do not know the unit rate, so we will use the slope formula to calculate its unit rate.

Slope formula:

m=y₂-y₁/x₂-x₁

Input two coordinate pairs:

m=(7,250)-(2,900)/(5)-(2)

m=4,350/3

m=1,450/g.

Therefore, answer choice C is correct