Question

paul bought a soft and a sandwich for 9.90. what equation may be used to find the price of each item if the sandwich cost 3.5 times as much as the soft drink?

Answer 1

So, let's say the soft drink equals y and the sandwich equals x.

x + y = 9.9

The sandwich costs 3.5 times as much as the soft drink

x = 3.5y

Therefore, we can replace x with 3.5y since they're the same thing

3.5y + y = 9.9 <-- That's the equation :)