1、3f+2f-7f
2. x-f+5x-4f
3.2a+3b+6a+9b-8a+12b
4. 3pq+7pq+4pq+pq
5 7xy-8wx+5xy-12xy
1、3f+2f-7f
2. x-f+5x-4f
3.2a+3b+6a+9b-8a+12b
4. 3pq+7pq+4pq+pq
5 7xy-8wx+5xy-12xy
1、(3+2-7)f = -2f
2、(X+5X)-(f+4f)=6x-5f
3、(2a+6a-8a)+(3b+9b+12b)=24b
4、(3+7+4+1)pq=15pq
5、(7xy+5xy-12xy)-8wx=-8wx
(3+2-7)f
(1+5)x-(1+4)f
(2+6-8)a+(3+9+12)b
(3+7+4+1)pq
(7+5-12)xy-8wx
1、3f+2f-7f
=(3+2-7)f
=-2f
2. x-f+5x-4f
=(x+5x)-(f+4f)
=6x-5f
3.2a+3b+6a+9b-8a+12b
=(2a+6a-8a)+(3b+9b+12b)
=0+24b
=24b
4. 3pq+7pq+4pq+pq
=(3+7+4+1)pq
=15pq
5 7xy-8wx+5xy-12xy
=(7xy+5xy-12xy)-8wx
=0-8wx
=-8wx
-2f
6x-5f
24b
15pq
-8wx
1、3f+2f-7f= -4f
2. x-f+5x-4f=6x-5f
3.2a+3b+6a+9b-8a+12b=21b
4. 3pq+7pq+4pq+pq=15pq
5 7xy-8wx+5xy-12xy= -8wx
-2f
6x-5f
24b
15pq
-8wx