ldcf.net
当前位置:首页 >> 2x+1/8=11/8求解方程 >>

2x+1/8=11/8求解方程

当1/2<x<2时 2-x+2x-1=8 x=7 不符题意 当x<1/2时 2-x+1-2x=8 -3x=5 x=-3/5 当x≥2时 x-2+2x-1=8 3x=11 x=3/11

41.2x8.1+11x1.25+53.7x1.9=41.2x8.1+11x1.25+(41.2x1.9+12.5x1.9)=41.2x(8.1+1.9)+1.25x(11+19)=412+37.5=449.5

解(1)由-2x^2+12x-8 =-2[x^2-6x+9-9]-8 =-2[(x-3)^2-9]-8 =-2(x-3)^2+10 由2(x-3)^2≥0 即-2(x-3)^2≤0 即-2(x-3)^2+10≤10 即-2x^2+12x-8≤10 故-2x^2+12x-8的最大值为10 即-2x^2+12x-8的值不可能等于11 (2)由x^2-x+1=0 得(x-1/2)^2+3/4=...

增广矩阵 = 4 2 -1 2 3 -1 2 10 11 3 0 8 r2+2r1 4 2 -1 2 11 3 0 14 11 3 0 8 r3-r2 4 2 -1 2 11 3 0 14 0 0 0 -6 所以 r(A)=2≠3=r(A,b) 故方程组无解.

=412×0.81+11×(8+1.25)+(412+125)×0.19 =412×0.81+11×8+11×1.25+412×0.19+125×0.19 =412×(0.81+0.19)+88+125×0.11+125×0.19 =412+88+125×(0.11+0.19) =500+125×0.3 =537.5

4/11-2X=4/3 X+8/1=12/7 7/2+X=1-3/1 4/11-4/3=2X X+8=12/7 3.5+X=-2 4/8=2X X=12/7-8 X=-2-3.5 0.25=X X=-44/7 X=-5.5

88.8x8.7+11.2x9.9-11.2x1.2 =88.8x8.7+11.2x(9.9-1.2) =88.8x8.7+11.2x8.7 =(88.8+11.2)x8.7 =100x8.7 =870

解:1.x= 2.x=3 3. x=5 4. x=

用换元法解方程:[8(x^2+2x)/x^2-1]+[3(x^2-1)/x^2+2x]=11,可设y=(x²+2x)/(x²-1),则原方程变形为8y+3÷y=11

(1)1.4x+9.8=22.4, 1.4x+9.8-9.8=22.4-9.8, 1.4x=12.6, 1.4x÷1.4=12.6÷1.4, x=9;(2)2(x-3)=11.6, 2x-6=11.6, 2x-6+6=11.6+6, 2x=17.6, 2x÷2=17.6÷2, x=8.8;(3)13x-x=144, 12x=144, 12x÷12=144÷12, x=12;(4)68-4.4x=24...

网站首页 | 网站地图
All rights reserved Powered by www.ldcf.net
copyright ©right 2010-2021。
内容来自网络,如有侵犯请联系客服。zhit325@qq.com