Answer :
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
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