若2x+3=5x-1则6x-2=

若2x+3=5x-1则6x-2=

5x－2x＝3＋1
3x＝4
x＝4/3
6x－2＝6×4/3－2＝8－2＝6.

比楼上简单一步,先求3x=4
所以6x=8
所以6x-2=6

3x^2-x=1
3x^2-x-1=0
6x^2-2x-2=0
6x^3 7x^2-5x 1990
=x(6x^2-2x-2) 9x^2-3x 1990
=9x^2-3x-3 1993
=3(3x^2-x-1) 1993
=0 1993
=1993