Ratio equivalent to 2:9 is 4:18, 6:27
If you multiply the same number to both numbers, the ratio would always be the same.
You paid $4.76 total for 7 notebooks. To figure out how much each individual notebook cost, you divide the total cost by the number of things you bought, so
Cost of One Notebook = Total Cost of Notebooks / Number of Notebooks = $4.76 / 7 = $0.68
This is the unit rate.
To buy three notebooks, you just calculate the total cost of three notebooks at this price point, so
Cost of Three Notebooks = Cost of One Notebook * 3 Notebo0ks = $0.68 * 3 = $2.04
Answer: 10x + 4y + 2
The terms with an x are considered like terms so they could be subtracted.
There’s two ways to substitute, but i think you mean if you know x but don’t know y. if that is true, then yes use substitution
