Answer: 51.75$
Step-by-step explanation: First, turn 15% into the decimal 0.15, then multiply by 45, which equals 6.75. Now add 6.75, which is the amount the waitress got tipped to 45, which equals 51.75$ total.
Because they are the same equation, just rewritten in a different way.
s = 4p
divide both sides by 4 to get the other equation:
(1/4)s = p
Given that,
Shelley's pet food store sold one customer 5 peanut butter biscuits for $3. She sold another customer 7 beef treats for $4.20.
For peanut, the cost is ratio is

For beef, the ratio is

If we take cross product of these items,

It implies, that the sale is in true proportion. From the cross product, we find that it is equal.