计算:2008+2008²-2009²
解方程:(5x+35)*(53x+26)-(5x+35)*(53x+37)=0
初二
计算:2008+2008²-2009²
解方程:(5x+35)*(53x+26)-(5x+35)*(53x+37)=0
初二
2008+2008²-2009²
=2008+(2008+2009)(2008-2009)
=2008+(2008+2009)(-1)
=2008-2008-2009
=-2009
(5x+35)*(53x+26)-(5x+35)*(53x+37)=0
(5x+35)(53x+26-53x-37)=0
(5x+35)(-11)=0
55x=385
x=7
1、原式 = 2008 + (2008+2009)×(2008-2009)
= 2008 + (-1)×(2008+2009)
= 2008 - 2008 - 2009
= -2009
2、(5x+35)×(53x+26)—(5x+35)×(53x+37)= 0
(5x+35)×(53x + 26 — 53x — 37)= 0
(5x+35)×(—11)= 0
5x + 35 = 0
x = -7