



 
Hi Ken, I assume that there is no PST on this item and the GST is $5\%.$ Suppose the the price of the item before the GST is added is $P$ dollars. Since you paid $\$2,319.45$ you know that \[1.05 \times P = 2,319.45.\] Divide both sides of this equation by $1.05$ to get \[P = \frac{2,319.45}{1.05}.\] The GST you paid is then the difference between $P$ and $\$2,319.45.$ Penny  


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences. 