Maths~~Mid-point formula
2013-08-07 2:45 am
If the mid-point of A (a-2,2a+3)and B(1-3b,2b+1)is P(6,3),Find the values of a and b.
回答 (2)
2013-08-13 4:42 am
✔ 最佳答案
first equation : (a-2)+(1-3b)=6 a-3b=7
a=7+3b
second equation : (2a+3)+(2b+1)=3
2a+2b= -1
two equations two unknowns
put a=7+3b into second equation
2a+2b= -1
2(7+3b)+2b= -1
14+6b+2b= -1
8b= -15
b= -15/8
put b=- 15/8 into first equation
a=7+3b
a=7+3(-15/8)
a=6/5/8
參考: myself
2013-08-07 4:53 pm
you made a minor mistake and hence the answer is wrong.
6= (a-2+1-3b)/2
12=a-1-3b
a=13+3b
3= (2a+3+2b+1)/2
6=2a+4+2b
3=a+2+b
a=1-b
13+3b=1-b
12=-4b
b=-3
a= 1-(-3)
a=4
6= (a-2+1-3b)/2
12=a-1-3b
a=13+3b
3= (2a+3+2b+1)/2
6=2a+4+2b
3=a+2+b
a=1-b
13+3b=1-b
12=-4b
b=-3
a= 1-(-3)
a=4
收錄日期: 2021-04-13 19:36:49
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https://hk.answers.yahoo.com/question/index?qid=20130806000051KK00302