Explanation for Question 4 From the Math (No Calc) Section on the 2017 May Sat
Question four, we're given two equations and then we have any 2 economics. The equilibrium price is defined as the price at which quantity demanded 3 and quantity supplied are equal. 4 If the quantity demanded D and the quantity supplied S in 5 terms of the price in dollars P are given by the equation above what 6 is it equally be in price? So here we do seem to have system 7 of equations where given the condition that D and S are equal. 8 Um, so that is how we are going to be approaching this problem. 9 Um, if DNS are equal, 10 that means that all of this is equal to all of this, 11 because that's what DNS equal. So we can just equal both of these sides 12 to each other. And we can say that 60 minus three, 13 over four P is equal to one over 14 four P. And now we just have one equation 15 with one variable, and we can just solve by isolating P we 16 can add three over four P to both sides and 17 get, we have one fourth plus 18 three over four, which just we, 19 um, the numerator keep the denominator. 20 And we have four, four that is equal to one. 21 So we have 60 equals one P or 22 60 equals P, which has answered choice B.