00:01
Here our is equation is derived from our equilibrium equation, which is y is equal to c plus i plus g.
00:08
Substituting our given equations in, we're going to get that y is equal to 100 plus 0 .8 times y minus t, plus 500, plus 0 .6y, minus 20r, plus g.
00:24
Now we are going to solve this for y.
00:27
We are going to get that y is equal to 1 divided by 1 minus 0 .8, plus 0 .2, times 100 plus 500, plus g minus 20r.
00:44
We're going to see that our slope of our is curve is negative 20 divided by our 1 minus 0 .8 plus 0 .2.
00:56
This means that our decrease in our interest rate is going to increase our income by 100 units.
01:04
Then for b, to find our equilibrium levels, we need to figure out the intersection of our is and our lm curves.
01:13
Substituting this in, we're going to get that y is equal to 1 divided by our 1 minus 0 .8 plus 0 .2, times the rest of our equation from up here...