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解下列方程:(1)5(x%5)+2(x)=0;(2)4x+...

(1)去括号得:5x-25+2x-24=0,移项合并得:7x=49,解得:x=7;(2)去括号得:4x+3=2x-2+1,移项合并得:2x=-4,解得:x=-2;(3)方程整理得:0.7+3x?22=15?50x5,去分母得:7+15x-10=30-100x,移项合并得:115x=33,解得:x=33115;(4)去...

方程变形得:x2+4x=1,配方得:x2+4x+4=5,即(x+2)2=5,开方得:x+2=±5,解得:x1=-2+5,x2=-2-5.

(1)把方程直接开平方得:x-5=±4,∴x 1 =-5-4=-9,x 2 =4-5=-1;(2)a=1,b=-4,c=1,∴x= -b± b 2 -4ac 2a = 4± 16-4 2 = 4± 2 3 2 =2± 3 ;(3)a=1,b=-4,c=5,∵△=b 2 -4ac=16-20=-4<0,∴次方程无解.(4)a=1,b=5,c=3,∴x= -b± b 2 -4...

(1)196x2-1=0,整理,得(14x+1)(14x-1)=0,令14x+1=0或14x-1=0,解,得x1=-114,x2=114.(2)4x2+12x+9=81整理,得x2+3x-18=0,即:(x+6)(x-3)=0令x+6=0或x-3=0,解,得x1=-6,x2=3.(3)x2-7x-1=0即:x=7±72+42=7±532,∴x1=7+532,...

(1) 两边开方,得2(x - 1) = 3(x - 5)或2(x - 1) = -3(x - 5), 分别得x = 13和x = 17/5 (2) 只好套公式: x = (7 ± √41)/2 (3) (x - 2)(x + 1) = 0 x = 2, x = -1

(1)logx+2(4x+5)-log4x+5(x2+4x+4)-1=0化为logx+2(4x+5)-2[logx+2(4x+5)]-1-1=0令t=logx+2(4x+5)上式化为:t?2t?1=0 即 t2?t?2=0 解得t=?1,t=2当logx+2(4x+5)=-1时解得x=-1或x=?94都不符合题意,舍去.当logx+2(4x+5)=2时...

(1)去括号得:4x+2=x+7,移项、合并同类项得:3x=5,系数化为1得x=53;(2)去分母得:4×2x-3(3x-2)=24,去括号得8x-9x+6=24,移项、合并同类项得:-x=18,系数化为1得:x=-18.

(1)x(x+1)=0,x=0或x+1=0,∴x1=0,x2=-1;(2)(2x+11)(2x-11)=0,2x+11=0或2x-11=0,∴x1=-112,x2=112;(3)(2x+1)(3x-2)=0,2x+1=0或3x-2=0,∴x1=-12,x2=23;(4)(x-4+5-2x)(x-4-5+2x)=0,(1-x)(3x-9)=0,1-x=0或3x-9=...

0.8x(0.5+x)=1.2 0.4+ 0.8x =1.2 0.8x = 0.8 x=1 检验 0.8*(0.5+1)=0.8*1.5 = 1.2(等于方程右侧)

(1)分解因式得:(x-1)(x+5)=0,可得x-1=0或x+5=0,解得:x1=1,x2=-5;(2)分解因式得:(2x-5+x+4)(2x-5-x-4)=0,解得:x1=13,x2=9;(3)方程移项得:5(x+2)-4x(x+2)=0,分解因式得:(5-4x)(x+2)=0,解得:x1=54,x2=-2;...

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