Question

If $\frac{a+1}{b}+3=\frac{4a}{b}$, then $b$ can be written as

• A. $b=\frac{3a+1}{3}$
• B. $b=\frac{-3a+1}{3}$
• C. $b=\frac{3a-1}{3}$
• D. $b=\frac{-2a+1}{3}$

Answer 1

The correct option is C $b=\frac{3a-1}{3}$

Given equation is: $\frac{a+1}{b}+3=\frac{4a}{b}$
$\therefore a+1+3b=4a$
$\therefore 3b=4a-a-1$

$\therefore b=\frac{3a-1}{3}$