Answer:
See below.
Step-by-step explanation:
Just like 18, continue with 19-21. Solve for x by rewriting each equation in log form.

When rewriting the form, the base of the exponent becomes the base of the log.
Answer:
Option B. 
Step-by-step explanation:
we know that
The frequency is equal to the number of cycles divided by the time
Remember that
1 cycle = 1 full wave to repeat itself
In this problem
From o to 12 seconds ------> there are 2 cycles
therefore
The frequency is equal to

Caution: you need to use the same units of measurement throughout. If the spring stretches by 21 cm when a 135 newton object is attached, then you must ask for the mass (in newtons) of a fish that would stretch the spring by 62.1 cm.
We will need to assume that the spring is not stretched at all if and when no object is attached to the spring.
Write the ratio
21.0 cm 135 newtons
------------- = --------------------
62.1 cm x
Solve this for x. This x value represents the mass of a fish that would stretch the spring by 62.1 cm. You can cancel "cm" in the equation above:
21.0 135 newtons
------ = --------------------
62.1 x
Then 21.0x = (62.1)(135 newtons). Divide both sides of this equation by 21.0 to solve it for x.
As 1 yard is equal to 3 feet , so 4 yard will be 12 feet !
so 13 foot > 4 yards