Paul bought a soft and a sandwich for $9.90. What equation may be used to find the price of each item if the sandwhich cost 3.5 times as much as the soft drink

Sandwich costs $7.70 and the soda costs $2.20

Step-by-step explanation:

First create a ratio:

The sandwich cost 3.5 more than the drink therefore the ratio is 3.5:1

Then add the two sides of the ratio together to get the total parts of the ratio

3.5+1 = 4.5

Now that we know the total parts of the ratio we can solve for one part by dividing the total cost $9.90 by the total parts of the ratio 4.5+

$9.90/4.5 = 2.20

Since we know that each part of the ratio is 2.20 we multiply both sides of the ratio by 2.20

3.5 * 2.20 = 7.70

1 * 2.20 = 2.20

The equation is 3.5x+x=9.9

The soft drink costs 2.2 and the sandwhich costs 7.7