Answer:
3
2
x
x
3
1
−
28
(
3
x
3
1
)
+
1
=
0
Let
u
=
3
x
Now
3
u
2
−
28
(
u
3
)
+
1
=
0
3
u
2
−
28
u
3
+
1
=
0
9
u
2
−
28
u
+
3
=
0
Using the quadratic equation
u
1
,
2
=
−
b
±
√
b
2
–
4
a
c
2
a
you get
u
=
28
±
√
28
2
−
4
×
9
×
3
2
×
9
u
=
28
±
√
784
−
108
18
u
=
28
±
√
676
18
u
=
28
±
26
18
u
=
54
18
or
u
=
2
18
u
=
3
or
u
=
1
9
Put
3
x
back in for
u
to get
3
x
=
3
or
3
x
=
1
9
3
x
=
3
1
or
3
x
=
3
−
2
Therefore,
x
=
1
or
x
=
−
2
Explanation:
