Question

Mark (✓) against the correct answer

If (2n + 5) = 3(3n − 10), then n = ?

(a) 5
(b) 3
(c) $\frac{2}{5}$
(d) $\frac{2}{3}$

Answer 1

$\begin{array}{l}\left(\text{a}\right)5\\ \text{We have:}\\ (2n+5)=3(3n-10)\\ \Rightarrow 2n+5=9n-30\\ \Rightarrow 2n-9n=-30-5\\ \Rightarrow \cancel{-}7n=\cancel{-}35\\ \Rightarrow n=\frac{\sout{3}{\sout{5}}^5}{{\sout{7}}_1}\\ \Rightarrow n=5\end{array}$