问题 解答题

(230+770)+450230+450+770+550

78+(89+11)3×7+3×15

125×8+10×889+78+11

(7+15)×3586-135-42

586-(135-42)(125+10)×8.

答案

(1)(230+770)+450,

=1000+450,

=1450;

(2)230+450+770+550,

=(230+770)+(450+550),

=1000+1000,

=2000;

(3)78+(89+11),

=78+100,

=178;

(4)3×7+3×15,

=3×(7+15),

=3×22,

=66;

(5)125×8+10×8,

=1000+80,

=1080;

(6)89+78+11,

=(89+11)+78,

=100+78,

=178;

(7)(7+15)×3,

=22×3,

=22;

(8)586-135-42,

=586-(135+42),

=586-177,

=409;

(9)586-(135-42),

=586-93,

=493;

(10)(125+10)×8,

=125×8+80,

=1000+80,

=1080.

问答题
多项选择题