计算： ${\left(a-b\right)}^2-b\left(2a+b\right)=$ ____。

已知x=2，y=﹣3是二元一次方程5x+my+2=0的解，则m的值为（　　）

B

Dear Tom,

    Thanks for your letter. Do you want to know about my evening? Well, I usually get home from work at 6:00 p.m. I cook dinner for my family—my parents, my sister, and my brother. After dinner I usually watch TV, play computer games or play chess. I like playing chess because my father works in a chess club. I take a shower at around nine o'clock and then go to bed at around nine thirty. Sometimes I read some books because I can learn something about my work. How about your evening? Write to me soon, please.

Best wishes,

Victor