What is the difference in price between the book and the pen?
\(RM 4 0 - RM 3 0 = RM 10\)
\(\begin{array} {rr} \space\space\space\\ \space\space\text{RM }4\space0 \\-\space\space\text{RM }3\space0 \\\hline\space1\space0 \\\hline \end{array}\)
Treat yourself with rewards for your hard work
