Question

去括号;a-(-b-c)=_____,-(q+b)+(c-b)=-______,

Answer 1

a-(-b-c)=a+b+c,

-(q+b)+(c-b)=-q-b+c-b=-q-2b+c,

-3（-x+2y)=3x-6y

a+(b-c)=a+b-c

a-(b+c)=a-b-c

n-3(4-2m)=n-12+6m

先去括号,在合并同类项：

(3x-1)-(3-5x)

=3x-1-3+5x

=8x-4