<趕`後日交`40 marks> 各位知識朋友 , 入黎幫我手 ar !!! ( 數學F.2 ) (3)

咁你應該知系要求x等如咩架la

1(a)

y=2x/x-2

y(x-2) =2x/x-2(x-2)

y(x-2)=2x

x=y(x-2)/2

1(b)

y=x+2/2-x

y(2-x)=x+2

x=y(2-x)-2

1(c)

y=3x+1/x-1

y(x-1)=3x+1

y(x-1)-1=3x

x=[y(x-1)-1]/3


2(a)

y=1/2x-1/5x

y=5/10x-2/10x

y=3/10x

10xy=3

x=3/10y

2(b)method 1

1/a+1/b=b/a

1/b=b/a-1/a

1/b=b-1/a

a/b=b-1

a=b(b-1)

2(b)method 2

1/a+1/b=b/a

b+a/ab=b/a

b+a=b/a X ab

b+a=b^2

a=b^2-b

a=b(b-1) <==== factorization

ko