Answer:
a8 = 512.
Step-by-step explanation:
This is geometric sequence with common ratio r = 2 and first term a1 = 4.
nth term = a1 r^(n-1)
So a8 = 4 2(^8-1)
= 4 * 2^7
= 4*128 = 512.
Answer:
x
=
2
±
√
7
Explanation:
there are no whole numbers which multiply to - 3
and sum to - 4
we can solve using the method of
completing the square
the coefficient of the
x
2
term is 1
∙
add subtract
(
1
2
coefficient of the x-term
)
2 to
x2
−
4
x
⇒
x
2
+2(−
2
)
x
+
4
−
4
−
3
=
0
⇒
(
x
−
2
)2
−
7
=0
⇒
(
x
−
2
)
2
=
7
take the square root of both sides
⇒
x
−
2
=
±
√
7
←
note plus or minus
⇒
x
=
2
±
√
7←
exact solutions
Leave the whole number alone for now. Divide 41 by 80 and you get 0.5125
So your answer is 9.5125
