Answer:
Step-by-step explanation:
1/R = 1/R1 + 1/R2
R = 15
R1 = 23
The best way to do this question is to convert the resistances to decimals.
1/R = 1/15 = 0.0666666
1/R1 = 1/23 = .04348
0.066666666 = 0.0438 + 1/R2 Subtract 0.0438 from both sides.
0.023188 = 1/R2 Take the reciprocal of both sides.
43.125 = R2
========================
You can use fractions if you prefer. But it will a lot messier.
1/15 - 1/23 = 1/R2
23/345 - 15/345 = 1/R2
8/345 = 1/R2 Take the reciprocal of both sides.
345/8 = R2
R2 = 43.125
