解方程:(x+1)(x+2)(x+3)(x+4)=120.

解方程:(x+1)(x+2)(x+3)(x+4)=120.


由原方程,得(x2+5x+4)(x2+5x+6)=120.設x2+5x=y,則(y+4)(y+6)=120.即y2+10y-96=0.所以(y-6)(y+16)=0.解得y=6或y=-16.當y=6時,x2+5x=6,則(x+6)(x-1)=0.解得x1=-6,x2=1;當y=-16時,x2+5x=-16,即x2+5x+16=0,該方程無解.綜上所述,原方程的解是:x1=-6,x2=1.



解方程25%x+40%x=5.2(1-75%)x=36 120-25%x=100 x/(1-24%)=1.14


25%x+40%x=5.2 0.65x=5.2x=8(1-75%)x=36 0.25x=36x=144120-25%x=100 0.25x=120-1000.25x=20x=80x/(1-24%)=1.14x=1.14x0.76x=0.8664



解方程,(x+25%)×2=120 120%x-x=24


(x+25%)×2=120
(x+0.25)*2=120
x+0.25=60
x=59.75
120%x-x=24
(1.2-1)x=24
0.2x=24
x=120



解方程5x*10/3+4x*10/3+120=5x+8


x=-112/25