Question

解下列方程: y-y-1/2=2-y+2/5; 3x-[3(x+1)-(x+4)]=1; 1/3(x+1)+1/4(x+2)+1/5(x+3)=4-1/6(x+4)

Answer 1

y-y-1/2=2-y+2/5
10y-5(y-1)=20-2(y+2)
10y-5y+5=20-2y-4
7y=11
y=11/7
3x-[3(x+1)-(x+4)]=1
3x-[2x-1]=1
x+1=1
x=0

1/3(x+1)+1/4(x+2)+1/5(x+3)=4-1/6(x+4)
1/3(x+1)+1/4(x+2)+1/5(x+3)+1/6(x+4)=4
1/3(x+1)+1/4(x+2)+1/5(x+3)+1/6(x+4)=4
1/3(2/(x+1)+1/(x+4))+1/4(x+2)+1/5(x+3)+=4
1/3(2/(x+1)+1/(x+4))+(5(x+3)+4(x+2))/20(x+2)(x+3))=4
1/3((2x+8+x+1)/(x+1)(x+4))+(9x+23)/20(x+2)(x+3)=4
(x+3)/(x+1)(x+4)+(9x+23)/20(x+2)(x+3)=4