3x + y = 2.2
7x + y = 3.8
更新1:
solidum點解你要delete答案?
更新2:
It is a easy question.
F.3 Maths(送分的)
回答 (5)
2008-04-19 4:47 am
✔ 最佳答案
3x + y = 2.2－－－(1)7x + y = 3.8－－－(2)
Form (1), y=2.2-3x－－－(3)
sub (3) into (2)
7x+(2.2-3x)=3.8
4x=1.6
x=0.4
sub x=0.4 into (3)
y=2.2-3(0.4)
y=2.2-1.2
y=1.0
2008-04-21 5:39 am
我明你想講咩 之後你又delete答案- -
我仲想選你做最佳- -
我仲想選你做最佳- -
2008-04-19 4:51 am
3x + y = 2.2 ----------(1)
7x + y = 3.8 -----------(2)
(2) - (1):
7x+y - (3x+y) = 3.8 - 2.2
4x = 1.6
x = 0.4
sub x=0.4 into (1):
3(0.4) + y = 2.2
1.2 + y = 2.2
y = 1
7x + y = 3.8 -----------(2)
(2) - (1):
7x+y - (3x+y) = 3.8 - 2.2
4x = 1.6
x = 0.4
sub x=0.4 into (1):
3(0.4) + y = 2.2
1.2 + y = 2.2
y = 1
2008-04-19 4:38 am
呢題一定唔係F.3
呢題係 F.2 first term maths curriculum 第 5 課教
呢題係 F.2 first term maths curriculum 第 5 課教
2008-04-19 4:19 am
7x + y = 3.8
7x = 3.8 - y
x = (3.8 - y) / 7
把以上代入x1
3 * ( (3.8 - y )/ 7 ) + y = 2.2
3 * ( (3.8 - y) / 7 ) = 2.2 - y
(3.8 - y )/ 7 = (2.2 - y)/ 3
11.4 - 3y = 15.4 - 7y
4y = 4
y = 1 代入 x2
7x + 1 = 3.8
7x = 2.8
x = 0.4
7x = 3.8 - y
x = (3.8 - y) / 7
把以上代入x1
3 * ( (3.8 - y )/ 7 ) + y = 2.2
3 * ( (3.8 - y) / 7 ) = 2.2 - y
(3.8 - y )/ 7 = (2.2 - y)/ 3
11.4 - 3y = 15.4 - 7y
4y = 4
y = 1 代入 x2
7x + 1 = 3.8
7x = 2.8
x = 0.4
參考: 自己
收錄日期: 2021-04-23 17:56:46
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