What are the roots of the equation x^2-5x-2=0?

Problem:
The quadratic formula states:
For
a
x
2
+
b
x
+
c
=
0
, the values of
x
which are the solutions to the equation are given by:
x
=
−
b
±
√
b
2
−
(
4
a
c
)
2
⋅
a

Substituting:
1
for
a

−
5
for
b

−
2
for
c
gives:
x
=
−
(
−
5
)
±
√
(
−
5
)
2
−
(
4
⋅
1
⋅
−
2
)
2
⋅
1

x
=
5
±
√
25
−
(
−
8
)
2

x
=
5
±
√
25
+
8
2

x
=
5
±
√
33
2

21/2 or 5/2