1/(x-10)+1/(x-6)=1/(x-7)+1/(x-9)
1/(x-10)-1/(x-9)=1/(x-7)-1/(x-6)
[(x-9)-(x-10)]/(x-10)(x-9)=[(x-6)-(x-7)]/(x-7)(x-6)
即是
1/(x-9)(x-10)=1/(x-6)(x-7)
x^2-13x+42=x^2-19x+90
6x=68
得出:x=8
经检验,X=8是方程的解
1)66x+17y=396725x+y=1200答案:x=48y=47(2)18x+23y=230374x-y=1998答案:x=27y=79(3)44x+90y=779644x+y=3476答案:x=79y=48(4)76x-66y=408230x-y=2940答案:x=98y=51(5)67x+54y=854671x-y=5680答案:x=80y=59(6)42x-95y=-141021x-y=1575答案:x=75y=48(7)47x-40y=85334x-y=2006答案:x=59y=48(8)19x-32y=-178675x+y=4950答案:x=66y=95(9)97x+24y=720258x-y=2900答案:x=50y=98(10)42x+85y=636263x-y=1638答案:x=26y=62(11)85x-92y=-251827x-y=486答案:x=18y=44(12)79x+40y=241956x-y=1176答案:x=21y=19(13)80x-87y=215622x-y=880答案:x=40y=12(14)32x+62y=513457x+y=2850答案:x=50y=57(15)83x-49y=8259x+y=2183答案:x=37y=61