Question

At a ceramic shop, each cup is $6.30 cheaper than each plate. If you totally spent $28.50 for 5 cups and 3 plates, what is the price of each cup and each plate?

Answer 1

Let
x-------------> the price of each cup
y-------------> the price of each plate

we know that

5x+3y=28.50----------> equation 1
and
x=y-6.30--------------> equation 2

I substitute 2 in 1
5*(y-6.30)+3y=28.50---------> 5y-31.5+3y=28.5-----> 8y=60
y=7.5
x=y-6.3---------> x=7.5-6.3---------> x=1.2

the answer is
the price of each cup is $1.2
the price of each plate is $7.5