Multiply the cost of an item or service by the sales tax in order to find out the total cost.<span>Make sure you put the sales tax into decimal form. You do this by taking the percentage and sliding the decimal point two places to the left: ...<span>Example: $60 (item cost) x .075 (sales tax) = $4.5 total sales tax.</span></span>
E^(xy) = 2
(xdy/dx + y)e^(xy) = 0
At point (1, ln2), dy/dx + ln2 = 0
dy/dx = -ln2
