Question

设长=x宽=yx-1=y+2x+y=26/2=13解得x=8,y=58-1=7边长为7cm

Answer 1

设规定x天

则甲x-2,乙x+6

合作是x/2天

所以(x/2)*1/(x-2)+(x/2)/(x+6)=1

两边乘2(x-2)(x+6)

x(x+6)+x(x-2)=2(x-2)(x+6)

x2+6x+x2-2x=2x2+8x-24

2x=24

x=12

答：规定12天