计算:(1/X+3)-(6/X*X-9)-(x-1/6-2X) 解说:1除以x+3 再减6除以x的平方-9 在减x-1除以6-2x

问题描述:

计算:(1/X+3)-(6/X*X-9)-(x-1/6-2X) 解说:1除以x+3 再减6除以x的平方-9 在减x-1除以6-2x
计算:1/(X+3)-6/(X*X-9)-(x-1)/(6-2X)
文字解说:1除以x+3 再减6除以x的平方-9 在减x-1除以6-2x

1/(x+3)-6/(x^2-9)-(x-1)/(6-2x)=(x-3)/[(x-3)(x+3)]-6/[(x-3)(x+3)]+(x-1)/[2(x-3)]=[2(x-3)-12+(x-1)(x+3)]/[2(x-3)(x+3)]=(x^2+4x-21)/[2(x-3)(x+3)]=(x+7)(x-3)/[2(x-3)(x+3)]=(x+7)/(2x+6)