Raymond B. answered 02/28/20
Math, microeconomics or criminal justice
set the two equations equal and solve for x or just subtract one equation from the other to eliminate p and solve for x
Either way you get .2x2 + 3x -20 =0
Multiply by 5 to simplify, a little
x2 + 15x -100 = 0
You can factor this, surprisingly as 100 = 20 x 5 and 20 -5 = 15 the middle term coefficient
(x+20)(x-5) = 0
x=-20, 5 ignore the -20 as x>0
x=5 is the demand and supply in equilibrium, or in units of 100, as x really is 500
Plug that into either of the original equations to get the price, p
p=.1(5)2 +2(5) +56 = 1/10 (25) + 10 +56 = 2.5 + 10 + 56 = 68.5
P=$68.5 at that price supply & demand are equal at 500 tents
That's a price of $68.50 per one hundred tents, which sells 500 tents
or plug 5 into the other original equation:
-.1(5)2 -5+ 76 = =-2.5 -5+76 = 68.5