數學題一問(6)

1)解方程式:
4x-3=2x-15
4x-2x=-15+3
2x=-12
x=-6

2)解方程式:
3(3x-4)=2x+9
9x-12=2x+9
9x-2x=9+12
7x=21
x=3

3)解方程式:
p-3
-------=0.15
4
(p-3)/4*4=0.15*4
p-3=0.6
p-3+3=0.6+3
p=3.6

4))解方程式:
3x+2 8x-24
------- = ----------
5 6
x=?
(3x+2)/5*5*6=(8x-24)/6*5*6
(3x+2)*6=(8x-24)*5
18x+12=40x-120
12+120=40x-18x
132=22x
6=x
x=6
5)一正方形2邊為3x+3和5x-11,求x的值
3x+3=5x-11
3+11=5x-3x
14=2x
7=x
x=7

6)m是三個連續奇數中最小的數,求這三個的積
mnp(no data)

7)Given two consecutive numbers.Three times the larger numbers minus the smaller one14.if x is the larger numbers, which of the following equations will help to find x ?
(don't know english)

1.4x-2x= -15+3
2x=-12
x= -6

2. 9x-12=2x+9
9x-2x=9+12
7x=21
x=3