(1)已知1/x+1/x=3,求3x-4xy+3y/x+2xy+y的值 (2)已知x为整数,且2/x+3+2/3-x+2x+18/x^-9为整数,求所有符合条件的x的值的和
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(1)已知1/x+1/x=3,求3x-4xy+3y/x+2xy+y的值 (2)已知x为整数,且2/x+3+2/3-x+2x+18/x^-9为整数,求所有符合条件的x的值的和
(1)已知1/x+1/x=3,求3x-4xy+3y/x+2xy+y的值 (2)已知x为整数,且2/x+3+2/3-x+2x+18/x^-9为整数,求所有符合条件的x的值的和
(1)已知1/x+1/x=3,求3x-4xy+3y/x+2xy+y的值 (2)已知x为整数,且2/x+3+2/3-x+2x+18/x^-9为整数,求所有符合条件的x的值的和
(1)
∵1/x+1/y=3
∴(y+x)/xy=3
∴x+y=3xy
(3X-4XY+3y)/(X+2XY+Y)
=[3(x+y)-4xy]/[(x+y)+2xy]
=(9xy-4xy)/(3xy+2xy)
=5/5
=1
(2)
2/x+3+2/3-x+2x+18/x^2-9
=[2(X-3)-2(X+3)+2X+18]/(X+3)(X-3)
=2(X+3)/(X+3)(X-3)
=2/(X-3)
∴X-3=±1,±2
∴X=4,2,5,1
符合条件x的值的和为4+2+5+1=12