00:01
So here we have a demand function, right? our demand function is the quantity of x is equal to 75 minus two times the price of x minus 1 .5 times the price of y.
00:12
Right.
00:13
So we want to calculate the price elasticity using the point formula, which is equal to the slope times the price over the quantity, right? that's the basic formula for elasticity.
00:29
So here, the slope, right, the slope, or if you want to think of the slope as dq, dp, the slope here is minus 2, right? that's my slope coefficient.
00:42
So this elasticity is minus 2 starting off, but we need to find p and q, right? well, we're given that p is 20, so we need to find q of x when the price is 20.
00:54
So q of x is 75, minus 2 outside of 20, minus 1 .1 .3.
00:59
Five outside of 10.
01:01
So that's 75 minus, right? so 75 minus 40 minus 15 is equal to 20...