Answer:
Step-by-step explanation:
This is an Arithmetic Series with common difference 4 and first term 3
so the nth term an = 3 + (n -1)4
= 4n - 1.
The sum of n terms
= n/2 (a1 + L)
= n/2(3 + 1671)
= 837n.
There are (1671-3) / 4 + 1 = 418 terms in the series,
so the total value of the series is 837*418
= 349,866.
.
Its 400 ..... hope that helps :)
Answer:
a : c = 7 : 10
Step-by-step explanation:
The two ratios (a : b and b : c) both have b in common, so to work out what a : c is, we can use b to 'bridge' the two ratios together.
However, in a : b, b is 4. But in b : c, b is 2. We need to make sure b is the same in both ratios before we can combine the ratios together. The easiest way to do this is to multiply b : c by 2 to get b : c = 4 : 10. Now b is 4 in both ratios.
So now, we can combine the two ratios together to get a : b : c = 7 : 4 : 10. Since we only want a : c though, we can just drop the b and get a : c = 7 : 10. No simplifying is necessary since the ratio is already in its simplest form.
Hope that helps! :)
Answer:
x < -4 or x > 7.
Step-by-step explanation:
We first determine the critical points by solving x^2 - 3x - 28 = 0:
x^2 - 3x - 28 = 0
(x - 7)(x + 4) = 0
x = 7, - 4
so the critical points are -4 and 7.
Create a Table (pos = positive and neg = negative):
Value of x< - 4 -4 < x < 7 x > 7
---------------------|----------- |--------------------- |---------------------
x + 4 NEG POS POS
x - 7 NEG NEG POS
(x + 4)(x - 7) POS NEG POS
So the function is positive (>0) for x < -4 or x > 7.
You can also do this by drawing the graph of the function.
