(1)若3a^2-a-2=0,则5+2a-6a^2=( ) (2)8.5×2013+2.6×2013-1.1×2013=( )

来源:学生作业帮助网 编辑:作业帮 时间:2024/11/08 16:38:41

(1)若3a^2-a-2=0,则5+2a-6a^2=( ) (2)8.5×2013+2.6×2013-1.1×2013=( )
(1)若3a^2-a-2=0,则5+2a-6a^2=( ) (2)8.5×2013+2.6×2013-1.1×2013=( )

(1)若3a^2-a-2=0,则5+2a-6a^2=( ) (2)8.5×2013+2.6×2013-1.1×2013=( )
(1)若3a^2-a-2=0,则5+2a-6a^2=(1)
(2)8.5×2013+2.6×2013-1.1×2013
=2013×(8.5+2.6-1.1)
=2013×10
=20130

答案是2013.

(1)
3a^2 -a -2 = 0 =>a-3a^2 = -2
5+2a-6a^2=5+2(a-3a^2)=5 + 2 *(-1) = 1
(2)
8.5×2013 + 2.6×2013 - 1.1×2013
=(8.5 + 2.6 -1.1)×2013
=10×2013
=20130