5x+2(x+9)=200
X=26 x+9=26+9=35。
A: Every photo album 26 yuan, every T-shirt 35 yuan.
(2) Buy M T-shirts and 50m photo albums.
1800—[35m+26 (50m) ]≥270 ①
1800—[35m+26 (50m) ]≤300 ②
To ①m≤230/9
(2) M≥200/9
So the solution set of inequality group is: 200/9≤m≤230/9.
∵m can only be a positive integer. The solution satisfying the condition is: m=23, 24, 25.
Therefore, * * * has three purchase schemes: scheme 1: buy 23 cultural shirts and 27 photo albums;
Option 2: buy 24 cultural shirts and 26 photo albums; Option 3: Buy 25 T-shirts and 25 photo albums.
Suppose that the fund for purchasing teachers' souvenirs is Y yuan.
Y =1800—[35m+26 (50m)] = 500-9m.
∵k=-9 ∴ According to the properties of linear functions, y decreases with the increase of m.
Therefore, when m=23, the funds for purchasing teachers' souvenirs are the most abundant. So choose option one.
Question: Use IS-LM model to explain the decision of national income and interest rate.
A: When the factors affe