Question

化簡求值：

19 8 9 +29 5 6 -9 17 18

89 1 2 -59 2 3

=______．

Answer 1

原式=

(19 8 9 -9 17 18 )+29 5 6

89 1 2 -59 2 3

=

( 179 9 - 179 18 )+ 179 6

179 2 - 179 3

=

2 9

1 6

=

4

3

．
故答案為：

4

3

．