bài 1 : Tính
a) -56+8.(11+7)
b) 47.(23+50)- 23 .(47+50)
c) 85.( 47-29)+29.(85-47)
d) -19.(16-25)+19.(-25-4)
e) 13.(55-29)-55.(13-29)
f) 44.(-50)-50.56
g) -47.69-31.47
bài 2 : tìm x :
a) 10.(x-7)-8.(x-4)=x
b) 9.(x+4)-4.(2x+15)=3
giúp mk vs ạ !