Question

please solve this fast fast​

Answer 1

Answer:

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Step-by-step explanation:

1. take lcm

2. multiply

3. substitute

4. simplify

Answer 2

Answer:

8Ω

Step-by-step explanation:

As the potential difference between B and D is zero, the circuit is said to be balanced. So, in a Wheatstone's bridge,

$\frac{AB}{AD} = \frac{BC}{DC}$

21Ω / 18Ω = (8x/8+x) + 3Ω /  6Ω             (In BC, 3Ω resistor and the parallel combination is in series.)

7Ω / 6Ω = (8x/8+x) + 3Ω / 6Ω

Denominators are the same, so they get canceled.

7Ω = (8x/8+x) + 3Ω

7Ω - 3Ω = 8x/8+x

4Ω * (8+x) = 8x

32Ω + 4x = 8x

4x = 32Ω

x = 32Ω/4

x=8Ω.

∴The unknown resistance is 8Ω.