I
f
x
-
y
=
4
a
n
d
x
y
=
21
,
f
i
n
d
t
h
e
v
a
l
u
e
s
o
f
x
3
-
y
3
.
Match the items on the right to the items on the left.
Check
OK
STEP-1
STEP-2
STEP-3
STEP-4
STEP-5