MATH F.1

解釋:
一個數字+10再*7就等於同一個數字*12再+2
先設該數字為x(x為代數)
(x+10)*7=12x+2
左手面: (x+10)*7
=x*7+10*7
=7x+70

右手面: 12x+2

7x+70=12x+2
1.先把有x的擺去一邊, 數字既放去另一邊
( 70-2=12x-7x)
2.作普通既+-數
( 68=5x )
5x=5乘x
3. 將所有數字放到一邊
(68/5=x)
完成
x=68/5

2008-06-10 15:51:29 補充：
68/5是假份數
必須跟題目作答
若題目要求點數
68/5=13.6

The result of adding 10 to a number and then multiplying it by 7 is equal to the result of mutiflying the number by 12 and adding 2 to it. Find the number.

(當一個數加10再乘7等於一個數乘12後加2. 此數是多少.)

let the number be X,

(X+10) * 7 = 12X +2
7X + 70 = 12X + 2
5X = 68
X = 13.6

the number is 13.6

Let the number be y
(y+10)7=12y+2
7y+70=12y+2
7y-12y=2-70
-5y=-68
5y=68
y=13.6
The number is 13.6