问题
填空题
含有字母的式子“5-1.2x+2+0.1x”可以化简为______,当x=0.4时,这个式子的值是______.
答案
5-1.2x+2+0.1x=7-1.1x,
把x=0.4代入上式得
7-1.1x,
=7-1.1×0.4,
=7-0.44,
=6.56,
故答案为:7-1.1x,6.56.
含有字母的式子“5-1.2x+2+0.1x”可以化简为______,当x=0.4时,这个式子的值是______.
5-1.2x+2+0.1x=7-1.1x,
把x=0.4代入上式得
7-1.1x,
=7-1.1×0.4,
=7-0.44,
=6.56,
故答案为:7-1.1x,6.56.