F.2 Maths

35. 6a/12ab
= 1/2b

36. 30xy/25x^2
= 6y / 5x

37.(ab+2ac)/2a
= b/2 + c

38.(2ax-2bx)/(4a-4b)
= 2x(a-b)/4(a-b)
= x/2

39.(a^2/b)(b^2/a^3)
= b/a

40.(15a^2/10ab)/(12ab/8b^2)
= (15a^2/10ab) * (8b^2/12ab)
= (5a/5a) * (4b/4b)
= 1

41.(1-x^2)/(x-1)
= (1^2 - x^2)/(x-1)
= (x+1)(x-1)/(x-1)
= (x+1)

42.(ax+bx+ay+by)/(x^2+2xy+y^2)
= a(x+y)+ b(x+y) / (x+y)^2
= (x+y)(a+b)/(x+y)^2
= (a+b)/(x+y)

43.[(2x-2y)/4a]/[(x-y)/a]
= [2(x-y)/4a] * [a/(x-y)]
= 2/4
= 1/2

44.[(5m-10n)/(2m+2n)]x[(2m+4n)/(4m-8n)]
= [5(m-2n)/2(m+n)] * [2(m+2n)/4(m-2n)]
= 10(m-2n)(m+2n)/8(m+n)(m-2n)
= 5[m^2-(2n)^2]/ [4(m+n)(m-2n)]

35. 6a/12ab =1/2b
36. 30xy/25x^2 =6y/125x
37.(ab+2ac)/2a=b/2+c
38.(2ax-2bx)/(4a-4b)=x/2
39.(a^2/b)(b^2/a^3)=唔識..
40.(15a^2/10ab)/(12ab/8b^2)=唔識..
41.(1-x^2)/(x-1)=唔識..
42.(ax+bx+ay+by)/(x^2+2xy+y^2)=唔識..
43.[(2x-2y)/4a]/[(x-y)/a]=唔識..
44.[(5m-10n)/(2m+2n)]x[(2m+4n)/(4m-8n)]=5/(m+n)乘m+n/2
本人小六,純粹試一試哦^^

2007-12-31 11:18:43 補充：
36. 30xy/25x^2 =6y/5x

35. 6a/12ab
=1/2b
36. 30xy/25x^2
=6y/5x
37.(ab+2ac)/2a
=(b+2c)/2
38.(2ax-2bx)/(4a-4b)
=x/2
39.(a^2/b)(b^2/a^3)
=b/a
40.(15a^2/10ab)/(12ab/8b^2)
=1
41.(1-x^2)/(x-1)
=-x-1
42.(ax+bx+ay+by)/(x^2+2xy+y^2)
=a+b/x+y
43.[(2x-2y)/4a]/[(x-y)/a]
=1/2
44.[(5m-10n)/(2m+2n)]x[(2m+4n)/(4m-8n)]
=5(m+2n)/4(m+n)

35. 1/2b
36. 6y/5x
37. (b+2c)/2
38. x/2
39. b/a
40. 9/8
41. -x-1
42. (a+b)/(x+y)
43. 1/2
44. [(5m-10n)/(2m+2n)]x(u mean multiply here?)[(2m+4n)/(4m-8n)]
44 ans: 5(m+2n)/4(m+n)

等陣，宜家計

2007-12-31 11:02:11 補充：
35. 6a/12ab = 1/2b36. 30xy/25x^2 = 6y/5x37.(ab+2ac)/2a = a(b+2c)/2a = (b+2c)/238.(2ax-2bx)/(4a-4b) = 2x(a-b)/4(a-b) = x/239.(a^2/b)(b^2/a^3) = b/a

2007-12-31 11:10:51 補充：
40.(15a^2/10ab)/(12ab/8b^2)=(15a^2/10ab)(8b^2/12ab)=141.(1-x^2)/(x-1)=(1-x)(1+x)/(x-1)=-(x-1)(1+x)/(x-1)=-(x+1)42.(ax+bx+ay+by)/(x^2+2xy+y^2)=[(a+b)x+(a+b)y]/(x+y)^2=(a+b)(x+y)/(x+y)^2=(a+b)/(x+y)

2007-12-31 11:11:11 補充：
43.[(2x-2y)/4a]/[(x-y)/a]=[2(x-y)/4a][a/(x-y)]=1/244.[(5m-10n)/(2m+2n)]x[(2m+4n)/(4m-8n)] = [5(m-2n)/2(m+n)]x[2(m+2n)/4(m-2n)]=5(m+2n)/4(m+n)