Is the curve:

According to Y=C+I+G+X-M, y =100+0.8yd+200-5r+100+50-(24+0.1y) (1).

Disposable income: yd=y-T=y-(20+0.25y) (2)

At the same time (1)(2) finishing: y=820- 10r.

Therefore, the equation of IS curve is y=820- 10r.

LM curve:

According to money supply equals money demand: M= 100=L=0.24y-2r.

Finishing: y=( 1250+25r)/3

Therefore, the equation of LM curve is y=( 1250+25r)/3.

2. When the commodity market and the money market are balanced at the same time, the income and interest rate at this time are the corresponding income and interest rate at the intersection of the is curve and the LM curve.

According to the problem 1, the equation of IS curve is y=820- 10r (3).

The equation of LM curve is y=( 1250+25r)/3 (4).

Simultaneous (3) and (4), y=600, r=22.

Therefore, when the commodity market and money market are balanced at the same time, the income is 600 and the interest rate is 22.