[tex]\\ \rm\hookrightarrow A=\left(\dfrac{r+b}{2}\right)f[/tex]
[tex]\\ \rm\hookrightarrow \dfrac{r+b}{2}=\dfrac{A}{f}[/tex]
[tex]\\ \rm\hookrightarrow f(r+b)=2A[/tex]
[tex]\\ \rm\hookrightarrow r+b=\dfrac{2A}{f}[/tex]
[tex]\\ \rm\hookrightarrow r=\dfrac{2A}{f}-b[/tex]
Answer:
Step-by-step explanation:
❁ Hello! ❁
A = (r+b/2)f
r+b/2 = A/f
f(r + b) = 2A
r + b = 2A/f
r = 2A/f - b
Success! ☺️