The price of each brush in the stationery department of Dongfeng Shopping Mall is 25 yuan, and the price of each calligraphy exercise book is 5 yuan. The shopping mall has formulated two promotion preferential schemes: Party A..
( 1)y A =5x+200，Y B =4.5x+225。
(2) Scheme A: 25× 10+50×5=500 yuan;
Scheme B: (25× 10+60×5)×0.9=495 yuan;
Two options: 25× 10+50×5×0.9=475 yuan,
So use plan A to buy 10 brushes and plan B to buy the rest.