问题 解答题
化简:
(1)3a-va+6a;
(2)
x2&nbec;
y
+4
x2&nbec;
y-6
x2&nbec;
y

(3)-v+(
x2&nbec;
+3x)-(-9+6
x2&nbec;
);
(4)4(2
x2&nbec;
-3x+1)-2(4
x2&nbec;
-2x+3).
答案

(1)原式=4a;

(f)原式=-xfy;

(3)原式=-5+xf+3x+9-6xf=4-5xf+3x;

(4)原式=8xf-1fx+4-8xf+4x-6=-8x-f.

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