1. Billy and Cindy have to share $600. Billy's share is twice as much as Cindy's. Finf Billy's share.
2. Find the values of the constants A and B in the foolowing indentity.
( A + 5B )x + ( 3A - 2B ) 三 13x + 5
PS. 三 係 indentity sign
Maths Problem (急!) (最佳 20 分)
2007-01-27 2:08 am
回答 (3)
2007-01-27 2:26 am
1. Let Cindy's share is X, then Billy'share is 2X
X+2X=600
3X=600
X=200
Billy has 400 shares.
-----------------------------------------
2. ( A + 5B )x + ( 3A - 2B ) 三 13x + 5
(A+5B)=13---(1),
3A-2B=5---(2),
From (1),
(A+5B)=13
A=13-5B---(3),
sub (3) into (2),
3(13-5B)-2B=5
39-15B-2B=5
34=17B
B=2---(4)
sub(4)into (1),
(A+5(2))=13
A=3
Therefore, A=3, B=2
X+2X=600
3X=600
X=200
Billy has 400 shares.
-----------------------------------------
2. ( A + 5B )x + ( 3A - 2B ) 三 13x + 5
(A+5B)=13---(1),
3A-2B=5---(2),
From (1),
(A+5B)=13
A=13-5B---(3),
sub (3) into (2),
3(13-5B)-2B=5
39-15B-2B=5
34=17B
B=2---(4)
sub(4)into (1),
(A+5(2))=13
A=3
Therefore, A=3, B=2
2007-01-27 2:21 am
1. let x be the cindy's share
2x be the billy's share
2x+x=600
3x=600
x=200
so billy's share is 2*200=$400
2x be the billy's share
2x+x=600
3x=600
x=200
so billy's share is 2*200=$400
2007-01-27 2:21 am
如果冇解錯...
1. Billy's share is twice as much as Cindy's.
Then if cindy=x, billy= 2x
3x = $600
x = $200
so, billy = 2x = $400
2.
( A + 5B )x + ( 3A - 2B ) 三 13x + 5
A + 5B = 13 ----- (1)
3A - 2B = 5 ----- (2)
(1):
A + 5B = 13
A = 13 - 5B ----- (3)
SUB (3) into (2)
3( 13 -5B ) - 2B = 5
39 - 15B - 2B = 5
39 = 5 + 17B
17B = 34
B = 2
since A = 13 - 5B,
A = 13 - 5(2)
A = 3
1. Billy's share is twice as much as Cindy's.
Then if cindy=x, billy= 2x
3x = $600
x = $200
so, billy = 2x = $400
2.
( A + 5B )x + ( 3A - 2B ) 三 13x + 5
A + 5B = 13 ----- (1)
3A - 2B = 5 ----- (2)
(1):
A + 5B = 13
A = 13 - 5B ----- (3)
SUB (3) into (2)
3( 13 -5B ) - 2B = 5
39 - 15B - 2B = 5
39 = 5 + 17B
17B = 34
B = 2
since A = 13 - 5B,
A = 13 - 5(2)
A = 3
收錄日期: 2021-04-13 13:43:17
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