Kathi and robert hawn had a pottery stand at the annual skipcack craft fair. they sold some of their pottery at the original price of $9.50 for each piece, but later decreased the price by $2. if they sold all 90 pieces and took in $713, find how many pieces they sold at the original price and how many pieces they sold at the reduced price?

19 pieces at original price and 71 pieces sold at reduced price.

Let x=number sold for original price, $9.50 and y = number sold at reduced price $7.50.
So we have 2 equations.
x+y=90 => x=90-y (eqn 1)
9.5x + 7.5y = 713. (eqn 2)
sub (eqn 1) => (eqn 2)
9.5(90-y) + 7.5y = 713
855-9.5y+7.5y = 713
855-713 = 2y
142 = 2y
y = 142/2
y = 71 (eqn 3)
sub (eqn 3) => (eqn 1)
x = 90 - 71
x = 19

Num of plants = (original#ofplants)*(1.6)^t