Answer:
20x + 8
Step-by-step explanation:
5*4x + 5*5 -17
20x +25 -17
20x + 8
Answer:
z ≈ 145.62
Step-by-step explanation:
using the sine ratio in the right triangle
sin18° = 
= 
( multiply both sides by z )
z × sin18° = 45 ( divide both sides by sin18° )
z = 
≈ 145.62 ( to the nearest hundredth )
Answer:
16 years
Step-by-step explanation:
Given data
Principal= $8500
Rate= 4.5%
Final amount= $17,323
The expression to find time in compound interest is given as
t= ln(A/P)/r
substitute
t= ln(17323/8500)/0.045
t= ln(2.038)/0.045
t=0.711/0.045
t= 15.8 years
Hence the total time is about 16 years
Answer:
√
8
≈
3
Explanation:
Note that:
2
2
=
4
<
8
<
9
=
3
2
Hence the (positive) square root of
8
is somewhere between
2
and
3
. Since
8
is much closer to
9
=
3
2
than
4
=
2
2
, we can deduce that the closest integer to the square root is
3
.
We can use this proximity of the square root of
8
to
3
to derive an efficient method for finding approximations.
Consider a quadratic with zeros
3
+
√
8
and
3
−
√
8
:
(
x
−
3
−
√
8
)
(
x
−
3
+
√
8
)
=
(
x
−
3
)
2
−
8
=
x
2
−
6
x
+
1
From this quadratic, we can define a sequence of integers recursively as follows:
⎧
⎪
⎨
⎪
⎩
a
0
=
0
a
1
=
1
a
n
+
2
=
6
a
n
+
1
−
a
n
The first few terms are:
0
,
1
,
6
,
35
,
204
,
1189
,
6930
,
...
The ratio between successive terms will tend very quickly towards
3
+
√
8
.
So:
√
8
≈
6930
1189
−
3
=
3363
1189
≈
2.828427
No, her current average is 225. She would need to score 350 points to get a 250.
