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by cartera » Sun Feb 08, 2009 3:35 am
2x+3y+4=0,4x+6y+a=0; what is the value of a when both functions have more than one solution?

OA 8

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by dubeystuts » Sun Feb 08, 2009 3:48 am
Ans 8 sounds right to me.

Ok so we have two equations

First 2x+3y+4=0
Second 4x+6y+a=0

We have been asked to calculate the value of X so we need to simplify the equations by trying to cancel out variables x and y somehow.

Now if i multiply first equation by 2 then the equation becomes

The first equation was 2x+3y+4=0; after multiplying by 2 it becomes
4x + 6y + 8 = 0;

Now if we subtract equation 2 from our new equation one we get

4x + 6y + 8 = 0 ------ eq 1
4x + 6y + a = 0 ---- eq 2
___________________________________

0 + 0 + 8-a = 0 which gives us a = 8.

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by dubeystuts » Sun Feb 08, 2009 3:48 am
Ans 8 sounds right to me.

Ok so we have two equations

First 2x+3y+4=0
Second 4x+6y+a=0

We have been asked to calculate the value of X so we need to simplify the equations by trying to cancel out variables x and y somehow.

Now if i multiply first equation by 2 then the equation becomes

The first equation was 2x+3y+4=0; after multiplying by 2 it becomes
4x + 6y + 8 = 0;

Now if we subtract equation 2 from our new equation one we get

4x + 6y + 8 = 0 ------ eq 1
4x + 6y + a = 0 ---- eq 2
___________________________________

0 + 0 + 8-a = 0 which gives us a = 8.