5. Friday morning the Matthews family goes to town to buy groceries. The following three options are available for cereal:
CEREAL
CEREAL
CEREAL
Option 1:
300 g for $3.89
Option 2:
450 g for $4.77
Option 3:
600 g for $6.59
Which option is the best buy? Justify your answer. (17)

Step-by-step explanation:

Hello!

To compare different prices of several brands of a product the best is to express the price for the same quantities of product.

Since the three options are original in 300g, 450g and 600g, I'll express all prices on a base of 100g of product. You can use simple rule of three for this:

Option 1

300g cost $3.89

100g cost

Option 2

450g cost $ 4.77

100g cost

Option 3

600g cost $ 6.59

100g cost

So:

Option 1: $1.296/ 100g

Option 2: $1.06/100g

Option 3: $1.098/100g

The cheapest option is number 2

I hope this helps!

Step-by-step explanation:

r²+8r=−7

Step 1: Subtract -7 from both sides.

r²+8r−(−7)=−7−(−7)

r²+8r+7=0

Step 2: Use quadratic formula with a=1, b=8, c=7.

r=