急急急急急急急急急急--------maths 工課

1）7（2x-1)-3(4x-5)=3-11(2-x)
14x-7- 12x +15 =3-22 + 11x
2x + 8 = -19 + 11x
+ 8 +19 = + 11x – 2x
27 = 9x
9x = 27
x = 27/9
x = 3 (Answer)

2) x-1/3-5/12=2/+3/15(/=份數線)
x-1/3-5/12=2/? +3/15 (漏了什麼 ?)

3）3x+1/5-5x-11/12=1- 1-7x/40
3x-5x+7x/40 = -1/5 +11/12
-2x +7x/40 = 11/12 – 1/5
-80x/40 + 7x/40 = 55/60 – 12/60
-73x/40 = 43/60
-73x/2 = 43/3
(-73x)3 = 43(2)
-219x = 86
219x = -86
x = -86/219 (answer)

4) x/3+x+5/7=x-4
x/3+5/7= -4
x/3= -4-5/7
x/3 =-33/7
x = -99/7 (Answer)

Please check question 3; You may type something wrong.

14x-7-12x+15=3-22+11x
8-3+22=11x-2x
27=9x
x=3


第二條2/?


第三條我計唔到

x/3+x+5/7=x-4
x/3+5/7= -4
x/3= -4-5/7
x/3 =-33/7
x = -99/7