Answer:
3
Step-by-step explanation:
Answer:
Lixin obtains 15 marks
Step-by-step explanation:
Lets write two equations based on the question where: <u>D= Devi and L=Lixin</u>
D=L+15 <em>- "devi scores 15 marks more than lixin"</em>
D=2L <em>- "devi obtains twice as many marks as lexin"</em>
Now, substitute 2L as D in the first equation we wrote: (D=L+15)
2L=L+15
Next, subtract L from both sides:
<u>L=15</u>
The first step is combining like terms. On the left side of the equation add all the numbers together that don't have and x (1/3 +2)
Hope this helped! Let me know if there is anything else I can do!
Answer: I subtracted 8 from both sides then divided 3 on both sides
Step-by-step explanation: welcome
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
