D math 唔識請教教我(要步驟)急急急急急!!!!

1) s/4 + s/5 =18
5s/20 + 4s/20 = 18
9s/20 = 18
9s = 18 x 20
9s = 360
s = 40

2) 7[2(x-3)+x] = 4[1-3(x+2)]
7( 2x-6 + x) = 4( 1-3x-6)
7(3x - 6) = 4 (-3x-5)
21x - 42 = -12x -20
33x = 22
x = 22/33
x = 2/3

3) 5(3-x)/8 - x+3/2 = 0
(15-5x)/8 - 8x/8 + 12/8 = 0
(15-5x-8x+12)/8 = 0
(15-5x-8x+12) = 0
-13x+27 = 0
27 = 13x
13x = 27
x = 27/13
x= 2+1/13

答住咁多先,我想你補充下
如果同一個分子/母,請用( ),因為好容易搞錯
例: 3x+2/3 ------------> (3x+2)/3
你補充左我再答,thx
答左ge,一定岩,我檢查過

2006-12-30 12:30:34 補充：
6. 4y-5d=5d-44y= 10d-4y = (10d-4)/48. y/z + a = 3 - 2y/5z5y/5z+ 2y/5z = 3-a7y/5z = 3-a7y = 5z(3-a)y = 5z(3-a)/7答住咁多先,我想你補充下如果同一個分子/母,請用( ),因為好容易搞錯例: 3x+2/33x+2 係分子,就寫成 (3x+2)/3

2006-12-30 12:41:22 補充：
4. (2a+3)/4 - (a+4)/3 =a+1[3(2a+3)]/12 - [4(a+4)]/12 = a+1(6a+9)/12- (4a+16)/12 = a+1(2a-7)/12 = a + 12a-7 = 12a + 12-10a = 1910a = -19a = -1.97. 3y/2 + (p-7y)/2= w (3y+p-7y)/2 = w-4y+p=2w-4y= 2w-py = (2w-p)/(-4)我唔明第5題----->5/6 (x-2) 係乜

1 ) s/4 + s/5 = 18
20(s/4) + 20(s/5) = 18(20)
5s + 4s = 360
9s = 360
s = 40
2) 7[2(x-3)+x] = 4[1-3(x+2)]
7[2x-6+x]=4[1-3x-6]
14x-42+7x=4-12x-24
14x+7x+12x=4-24+42
33x=22
x=1又2分之1
3) 5(3-x)/8 - x+3/2 = 0
16[5(3-x)/8 - 16[x+3/2] = 0
2[15-5x] - 8x+24 = 0
30-10x - 8x+24 = 0
-10x-8x = 0-24-30
-18x = -54
x=3
4) 2a+3/4 - a+4/3 =a+1
12(2a)+12(3/4) - 12(a)+12(4/3) = 12(a)+12(1)
24a+9-12a+16 = 12a+12
24a-12a-12a=12-9-16
a=-26
5) - 8) 唔識 ，sorry

1. s/4+s/5=18
5s/20+4s/20=18
9s/20=18
9s=18*20
s=360/9
=40

2.7[2(x-3)+x] = 4[1-3(x+2)]
7(2x-6+x) =4(1-3x-6)
7(3x-6) =4(-5-3x)
21x-42 =-20-12x
21x+12x =-20+42
33x =22
x =22/33
x =2/3

1) 通分母先,,/\/\
4同5既公倍數係 20,,記得上使都要剩返,,所以係 (5S+4S)/20 = 18
咁將 除20調過去變18*20,,咁你就計到啦,,/\/\

其他既你試下先啦,, 記得要先乘除後加減,,/\/\

due to the reason of word limit, hence I'll email for the solution~

2006-12-30 11:56:47 補充：
pls let me know your e-mail address, thx.