x
2
−
4
x
−
5
=
0
(
x
−
5
)
(
x
+
1
)
=
0
x
=
5
o
r
x
=
−
1
4
x
2
−
3
x
−
10
=
0
4
x
2
−
8
x
+
5
x
−
10
=
0
4
x
(
x
−
2
)
+
5
(
x
−
2
)
=
0
(
4
x
+
5
)
(
x
−
2
)
=
0
x
=
−
5
4
o
r
x
=
2
36
x
2
−
9
=
0
(
6
x
+
3
)
(
6
x
−
3
)
=
0
x
=
−
1
2
o
r
x
=
1
2
2
x
2
+
6
x
+
3
=
0
(Answer to 2d.p.)
U
s
i
n
g
t
h
e
q
u
a
d
r
a
t
i
c
f
o
r
m
u
l
a
−
b
±
b
2
−
4
a
c
2
a
x
=
−
6
±
6
2
−
4
(
2
)
(
3
)
2
(
2
)
x
=
−
6
±
12
4
x
=
−
0.63
o
r
x
=
−
2.37