一3x十(2x一3)一2(4x一2)=-3x+2x-3-8x+4=(-3x+2x-8x)+(-3+4)=-9x+1
4x十3(2x一3)=12一(x十4)4x+6x-9=12x--410x-9=12x-4 两边-10x+42x=-5 x=-2.5
2x3十3x4十4x5十…十17x18=1/3*(17*18*19-1*2*3)=1936
3x[2x+1]=4x+26x^2+3x-4x-2=06x^2-x-2=0(3x-2)(2x+1)=0 x1=2/3 x2=-1/2
3(x十4x)二45,3*5x二45,x=3.
(3x一4).(3x十4)一(2x十3).(2x一3)=9x^2-16 -(4x^2-9)=5x^2 -7
3x^2+2x-1-(3x^2-2x+3)=3x^2+2x-1-3x^2+2x-3=4x-4∴x>1时 3x^2十2x一l>3x^2一2x十3 x=1时 3x^2十2x一l=3x^2一2x十3x 评论0 0 0
原式=x十2x-2-3(x十2) =x十2x-2-3x-6 =(x十2x-3x)-(2+6) =-8
4分之3x十3分之2x=34 解:9/12x+8/12x=34 17/12x=34 x=34*12/17 x=24 行家正解,不明白可以追问!祝您学习进步 满意请点击下面的【选为满意回答】按钮,o(∩_∩)o谢谢
17一2(3x十4)=3一2(x一1)解17-6x-8=3-2x+2-6x+2x=3+2-17+8-4x=5-17+8-4x=-12+8-4x=-44x=4解得x=4/4=1