1.
Which statement below is
not
correct?
A.
(
x
+ 2)
2
=
x
2
+ 4
x
+ 4
B.
(3
a
+ 1)
2
= 9
a
2
+ 6
a
+ 1
C.
(5
y
- 7)
2
= 25
y
2
+ 70
y
+ 49
D.
(2
b
- 5)
2
= 4
b
2
- 20
b
+ 25
Hint
2.
Find the product of
x, x
– 2, and
x
+ 2.
A.
x
3
- 4
x
B.
x
3
+ 4
x
2
+ 4
x
C.
x
3
- 4
D.
x
3
+ 4
x
Hint
3.
Which equation represents the square of a sum?
A.
(
a
+
b
)
2
=
a
2
+ 2
a
b
+
b
2
B.
(
a
+
b
)(
a
–
b
) =
a
2
–
b
2
C.
(
a
+
b
)(
a
–
b
) =
a
2
+
b
2
D.
(
a
–
b
)
2
=
a
2
– 2
a
b
+
b
2
Hint
4.
Which equation represents the product of a sum and a difference?
A.
(
a
+
b
)(
a
–
b
) =
a
2
+
b
2
B.
(
a
+
b
)
2
=
a
2
+ 2
a
b
+
b
2
C.
(
a
–
b
)
2
=
a
2
– 2
a
b
+
b
2
D.
(
a
+
b
)(
a
–
b
) =
a
2
–
b
2
Hint
5.
Find the product (12
j
+ 3
k
)(12
j
– 3
k
).
A.
144
j
2
– 9
k
2
B.
144
j
2
+ 9
k
2
C.
24
j
+ 6
k
D.
24
j
Hint