Here’s a photo of my working out. There’s heaps of ways to do this but this is what I got...
Answer:
-8
Step-by-step explanation:
-3x + 7x - 8 = 34 + 9x - 2
-3x + 7x - 9x = 34 - 2 + 8
-5x = 40|: (-5)
x = -8
We will use the Reminder theorem.
The polynomial f ( x ) is divisible by x - a when f ( a ) = 0.
For the 1st one:
f ( - 2 ) = ( - 2 )³ + 7 · ( - 2 )² + 14 · ( - 2 ) + 8 =
= - 8 + 28 - 28 + 8 = 0
For the 2nd one:
f ( 5 ) = 3 · 5³ - 12 · 5² - 4 · 5 - 55 =
= 375 - 300 - 20 - 55 = 375 - 375 = 0
Answer;
1. ( x + 2 )
2. ( x - 5 )
Sure, what's the question?
Sum of the First n Terms of a Geometric Sequence
Given a geometric sequence (or series) with a first-term a1 and common ratio r, the sum of the first n terms is given by:
We are given the series:
Before calculating the required sum, we need to find the common ratio. It's defined as the division of two consecutive terms. For example, using the first two terms:
The first term is a1 =120. Now apply the formula:
Operating:
Calculating: