Answer:
(D) xy/(x + y)
Step-by-step explanation:
To find r in terms of x and y
Given,
- two resistors with resistances x and y are connected in parallel
- r is the combined resistance of these two resistors
- the reciprocal of r is equal to the sum of the reciprocals of x and y
Then,
1/r = 1/x + 1/y
1/r = (y + x)/xy
Find the reciprocal of both sides
r = xy/(x + y)
The right answer is option (D) xy/(x + y)
They cancel each other out because one is + and the other is -.
<h2>○=> <u>Correct option</u> :</h2><h2>

</h2><h3>○=> <u>Steps to derive correct option</u> :</h3>
We know that :

So, let the diameter of this circle be x.
Which means :





Thus, the radius of the circle Robert drew = 6 m
Since the circle in option B has a radius of 6 m, it is the circle Robert drew.
▪︎<em>Therefore, the correct option is (B)</em>
Answer:
a) x - 4
Step-by-step explanation:
Given: four inches less than Kimi
Let "x" be Kimi
Four inches less than means subtraction
Therefore, it is x-4.
Answer: a) x - 4
Thank you.