Question 348445
set PerStone$=n
n*44+7$=73$ //PerStone$ multiple NumberOfStones plus Gravel$ equals to Totalcost
n*44=66$   //minus 7 on each side of the equation
n=1.5$     //divide 44 on each side of the equation
PerStoneCost=1.5$

//Recheck
1.5$*44=66$ //PerStone$ mutiple NumberOfStones equals Stones$
66$+7$=73$ //Stones$ plus Gravel$ equals Totalcost

//Answer
The cost of each paving stone is $1.5.

//I'm a student not a tutor...please forgive me and warn me if any errors appeared.