Let's begin by listing out the data given to us:
Price of a new bike (with 10% discount)with 10
To calculate the price before the 10% discount, we can use simple proportion
(100 - 10)% =# = $
100% = x
[tex]\begin{gathered} (100-10)\text{ \% = \$423 } \\ 100\text{ \% = x} \\ \text{Cross multiply, we have:} \\ x(100-10)=100\cdot423 \\ 100x-10x=42300 \\ 90x=42300 \\ \text{Divide both sides by 90, we have:} \\ x=\frac{42300}{90}=\text{ 470} \\ x=\text{ \$470} \end{gathered}[/tex]The price of the bike before the reduction is $470