Answer:
Denote O as center of circle, draw OA, OC.
As property of tangent line from outside of circle (angle OAD = angle OCD = 90 deg):
=> AOC + D = 180
Moreover, angle AOC = 2 x angle B = 2 x 65 = 130
=> D = 180 - 130 = 50 deg
Hope this helps!
:)
0.03(3-0.5)
0.03(2.5)
0.075
Answer:
a
x
2
+
b
x
+
c
=
0
the two roots of the equation take the form
x
1
,
2
=
−
b
±
√
b
2
−
4
a
c
2
a
So, start by adding
−
5
to both sides of the equation to get
2
x
2
+
x
−
5
=
5
−
5
2
x
2
+
x
−
5
=
0
Notice that you have
a
=
2
,
b
=
1
, and
c
=
−
5
. This means that the two solutions will be
x
1
,
2
=
−
1
±
√
1
2
−
4
⋅
2
⋅
(
−
5
)
2
⋅
2
x
1
,
2
=
−
1
±
√
41
4
You can simplify this if you want to get
x
1
=
−
1
+
√
41
4
≅
1.35078
and
x
2
=
−
1
−
√
41
4
≅
−
1.85078