Thursday, July 14, 2011

if 2a - 3c = 8 and a/2 = (2c+1)/3, find a and c.

Given that :


2a - 3c = 8
.................(1)


a/2 =
(2c+1)/3


Let us multiply by
6:


==> 6a/2 =
6(2c+1)/3


==> 3a =
2(2c+1)


==> 3a = 4c +
2


==> 3a - 4c = 2
...................(2)


Now we will solve the system using
the elimination method.


-3*(1)
+ 1*(2):


==> -6a + 9c =
-24


==> 6a - 8c =
4


==> c =
-20.


Now we will substitute in
(1).


==> 2a- 3c =
8


==> 2a - 3(-20) =
8


==> 2a + 60 =
8


==> 2a =
-52


==> a = -
26


Then, the answer is: a =
-26 and c = -20

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