小六方程式3題,急,20點!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

(1)
設n 是顏色筆總數

n x 2/9 + n x 1/6 = 14
n x (2/9 + 1/6) = 14
n x 7/18 = 14
n = 36

所以共有36枝

(2)
設n 是波子總數
n x 2/5 = n x 3/8 +1
n x 2/5 - n x 3/8 = 1
n x (2/5 - 3/8) = 1
n x (1/40) = 1
n = 40
所以共有40粒

(3)
設n 是圖案總數
n x 3/7 +3 = n x (1 - 3/7)
3 = n x (4/7 - 3/7)
3 = n x 1/7
n = 21
所以共有21個圖案


I hope the information can help you.

1. a x ( 2/9 + 1/6 ) = 14
a x ( 12/54+9/54 ) = 14
a x 21/54 = 14
a = 14 x 54/21
a = 36


2. w x ( 2/5 - 3/8 ) = 1
w x ( 16/40 - 15/40 ) = 1
w = 40


3. m x ( 4/7 - 3/7 ) = 3
m = 21

1.設三盒顏色有x枝筆
x(2/9) +x(1/6)=14
通分母
x=36枝
2.設波子x粒
(2/5)x - (3/8)=1
通分母
x=40粒
3設圖案x個..心形圖案佔4/7 ( 因:1-3/7 )
(4/7)x-(3/7)x=3
通分母
x=21
解題時留意題目提供的資料..以及題目是哪在一課學的,,知道這些就好快會答到

設y是顏色筆總數

y x 2/9 + n x 1/6 = 14
y x (2/9 + 1/6) = 14
y x 7/18 = 14
y = 36

共有36枝

(2)
設y是波子總數
y x 2/5 = n x 3/8 +1
y x 2/5 - n x 3/8 = 1
y x (2/5 - 3/8) = 1
y x (1/40) = 1
y = 40

共有40粒

(3)
設y是圖案總數
y x 3/7 +3 = y x (1 - 3/7)
3 = y x (4/7 - 3/7)
3 = y x 1/7
y = 21

21個圖案

1. a x ( 2/9 + 1/6 ) = 14
a x ( 12/54+9/54 ) = 14
a x 21/54 = 14
a = 14 x 54/21
a = 36


2. w x ( 2/5 - 3/8 ) = 1
w x ( 16/40 - 15/40 ) = 1
w = 40


3. m x ( 4/7 - 3/7 ) = 3
m = 21

2. (2/5) x - (3/8) x = 1

3. (1-3/7) x - (3/7) x = 3