4X/5x—2+5x—2/4x=17/4

来源：学生作业帮助网编辑：作业帮时间：2024/05/05 02:23:01

4X/5x—2+5x—2/4x=17/4
4X/5x—2+5x—2/4x=17/4

4X/5x—2+5x—2/4x=17/4
令a=4x/(5x-2)
则(5x-2_)/4x=1/a
a+1/a=17/4
两边乘4a
4a²-17a+4=0
(4a-1)(a-4)=0
a=1/4,a=4
4x/(5x-2)=1/4
5x-2=16x
x=-2/11
4x/(5x-2)=4
5x-2=x
x=1/2
所以x=-2/11,x=1/2

y=2e^2x
y'=2e^2x*(2x)'=4*e^2x
dy/dt=2t*e^t+t²e^t=(t²+2t)*e^t
d²y/dt²=(2t+2)e^t+(t²+2t)e^t=(t²+4t+2)e^t
dx/dt=(t+1)e^t
d²x/dt²=(t+2)*e^t
所以d²y/dx²=(d²y/dt²)/(d²x/dt²)=(t²+4t+2)/(t+2)

*-----------------------------------------------*| 6 4 X | 8 X X | X X 5 || X X X | X X X | X 7 8 || X X X | X X X | X X X ||---------------+---------------+--------------- || X X X | X X X | 5 1 X || X X X | X 6 X | X X X || 8 X X | 3 5 X | 2 X X || 求一个数独答案X X X 9 X X X 8 2 X 6 3 X X 1 4 X 99 X 8 X X X X X XX X X 6 7 X 3 X XX 4 6 X 5 X 2 9 XX X 7 X 2 3 X X XX X X X X X 7 X 17 X 4 3 X X 6 2 X6 3 X X X 7 X X X x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少? 在9x9的方格中,把1——9这9个数字填入方格中,每行每列都填这9个数,横竖都不能重复,8 X X X X X X X X X X 3 6 X X X X X X 7 X X 9 X 2 X XX 5 X X X 7 X X XX X X X 4 5 7 X XX X X 1 X X X 3 XX X 1 X X X X 6 8X X 8 5 X X X 1 XX (4/x-5)+(x-3)/(12-x)=(x-45)/(x^2-17x+60) (x-3/x-2)-(x-2/x-1)=(x-5/x4) -(x-4/x-3) x-2x+3x-4x+5x.+99x-100x=25求解 2x+3x+4x+5x+x+6x+7x=100 x(x+1)+(x+2)+(x+3)+(x+4)+(x+5) = 27求x x+2/x+1-x+4/x+3=x+6/x+5-x+8/x+7 x=? 写过程x(x-1)+2x(x+1)-3x(2x-5)-x(3x-2)+2x(2-x)=-5x(x-2)-4 通分x+4/x*x+4x与x-5/x(x-5)-2(x-5) x+2/x+1-x+3/x+2-x+4/x+3+x+5/x+4 (x+3x+5x...+2009x)-(2x+4x+6x+...+2010x) x^5-x^4+x^3-x^2+x-1 x^6-x^5+x^4-x^2+x-1 4X/5x—2+5x—2/4x=17/4 解方程；x/x-4=5x/x-2