Answer:
f=21
Step-by-step explanation:
The equation you could write is -4f=-84. Solving this (dividing by -4 on both sides), your answer is that f=21.
Answer:

Step-by-step explanation:


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%.
Answer:
6
Step-by-step explanation:
The maximum value of the sin function is at
, when sin is equal to 1. Since you need to multiply pi/12 by 6 to get to pi/2, the maximum amount of people will be at the square after 6 hours. Hope this helps!