Make r subject of the formula given that \(\frac{x}{r+a}=\frac{a}{r}\)
A
\(\frac{a^{2}}{(x-a)}\)
B
\(\frac{a^{2}}{(x+a)}\)
C
\(\frac{a}{x-a}\)
D
\(\frac{a}{x+a}\)
Verified Correct Answer: A.
Step-by-Step Mathematical Solution
\(\frac{x}{r + a} = \frac{a}{r}\)
\(\implies rx = ar + a^{2}\)
\(rx - ra = a^{2} \implies r = \frac{a^2}{x - a}\)
Source: Myschool Past Questions Archive (Record #3358)