化简求值1/(x+1)-[(x+3)/(x^2-1)] / [(x^2+4x+3)/(x^2-2x+1)]其中x=-32.已知a/b=2/7,求[49(a^4) -4(b^4)] / [7(a^3)b + 2a(b^3)]的值.以上
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/13 01:15:53
化简求值1/(x+1)-[(x+3)/(x^2-1)] / [(x^2+4x+3)/(x^2-2x+1)]其中x=-3
2.已知a/b=2/7,求[49(a^4) -4(b^4)] / [7(a^3)b + 2a(b^3)]的值.以上
1.1/(x+1)-[(x+3)/(x^2-1)] / [(x^2+4x+3)/(x^2-2x+1)]
=1/(x+1)-{(x+3)/[(x-1)(x+1)]} / {[(x+1)(x+3)]/[(x-1)^2]}
=1/(x+1)-{(x+3)[(x-1)^2]}/[(x-1)(x+1)^2(x+3)]
=1/(x+1)-(x-1)/[(x+1)^2]
=(x+1)/[(x+1)^2]-(x-1)/[(x+1)^2]
=2/[(x+1)^2]
=2/[(-3+1)^2]
=1/2
2.[49(a^4) -4(b^4)] / [7(a^3)b + 2a(b^3)]
={[7(a^2) -2(b^2)][7(a^2) +2(b^2)]} / {[7(a^2) + 2(b^2)]ab}
=[7(a^2) -2(b^2)]/ (ab)
=7(a/b) -2(b/a)
=7*(2/7)-2*(7/2)
=2-7
=-5
化简求值:4x-[3x-2x-(x-3),其中x=1/2化简求值,
化简求值(x+1)(x+2)(x+3)(x+4)-24化简求值.
化简求值:4x-[3x-2x-(x-3),其中x=1/2
(x+3)(x-3)-(x-2)(x+1),其中x=-2 (化简求值)
(x-2)(6x-5)-7x(x-3),其中x=-1化简求值,
化简求值(x+3)(x-2)+(x-1)(x+3)-2(x²-x+8)其中x=2
化简求值:x²(x²-x-1)-x(x²-3x),其中x=-2
(x+3)2次方-(x+1)(x-1),其中x=1.化简求值
化简求值:5x-[2x²-(-5x+1)]其中x=-3快
【化简求值】(x分之x+2 - x-2分之x-1)÷x分之x-4【化简求值】(x分之x+2 - x-2分之x-1)÷x分之x-4x=3
化简求值:[3/x-1-(x-1)]除以x^2-4x+4/x-1,其中x=-1
化简求值,(3x/x-1-x/x+1)/x/x2-1,其中x=根号2-2
化简求值:[3x/(x-1)-2x/(x+1)*(x2-1)/x 其中x=根号5 -5
化简求值:(x^2-4x)/(x+1)除以(4-x)/x,其中x=-3
(3x+2y-1)(3x-2y+1)-(x+y)(x-y)化简求值其中,x=三分之一 y=二分之一 化简求值
化简求值 已知[x-(x/x+1)]*(x+1/x^2+3x+2)除以(x^2-2x/x^2-4),其中x=-1/2
数学-化简求值难题(1)化简求值:(X+2/X^2-2X - X-1/X^2-4X+4) ÷ X^2-16/X^2+4X,其中X=2+根号2.(2)化简求值:(3X/X+2 - X/X-2)+ 2X/X^2-4.其中X=4-根号5.
化简求值x/(x-1)-3/(x-1)(x+2)-1x=-(2/3)