6.3去括号,第六章 整式的加减,学校 ,a+(b-c),a+b-c,a+(b-c),a+b-c,=,a-(b-c),a-b+c,a+(b-c),a+b-c,=,a-(b-c),a-b+c,=,a,4x,4x,2x,2x,a+(-b+c) =,+( ),-b+c,a,a-(-b+c) =,-( ),b c,- +,+ -,(1) +(a4b)；,(2) (a4b)；,(3) (a4b)；,(4) (p4q)；,(5) (m2n) ( 2m+4n)；,(6) (3x+2y) +(x 2y),直接去括号：,a4b,a+4b,a4b,p+4q,m2n+2m 4n,3x 2y + x 2y,先去括号，再合并同类项:2x2 3(2xx2),2x2 3(2xx2),= 2x2 ( x x2),= 2x2 6x+3x2,= 5x2 6x,注意：括号前的“”和数字,6,3,下列去括号正确吗？如有错误，请改正., 5x(2x1)x2=5x2x1x2 （ ）,5x(2x1)x2=5x2x1 x2,（ ）,（ ）,a,a+(-b+c) =,+( ),-b+c,a,a-(-b+c) =,-( ),b c,- +,+ -,探索去括号法则,去括号时应注意,1. 括号前的符号,2. 括号前的系数,3. 绝不能漏项,
