Answer:
x^4 - 11·x^2 + 18 = 0
I use Vieta's formulas
-9·(-2) = 18 and -9 + (-2) = -11
(x^2 - 9)·(x^2 - 2) = 0
(x + 3)·(x - 3)·(x + √2)·(x - √2) = 0
The circumference of the circle would be 25.13.
Answer: -2
Step-by-step explanation: 4-8= -4 then it ends up being -2r-4=0
Then you add 4 to 0 so -2r=4 then divide
Given:
The rate of interest on three accounts are 7%, 8%, 9%.
She has twice as much money invested at 8% as she does in 7%.
She has three times as much at 9% as she has at 7%.
Total interest for the year is $150.
To find:
Amount invested on each rate.
Solution:
Let x be the amount invested at 7%. Then,
The amount invested at 8% = 2x
The amount invested at 9% = 3x
Total interest for the year is $150.

Multiply both sides by 100.


Divide both sides by 50.


The amount invested at 7% is
.
The amount invested at 8% is

The amount invested at 9% is

Thus, the stockbroker invested $300 at 7%, $600 at 8%, and $900 at 9%.