Question

3x -4y - 15=0, x + y +2=0
solve eliminations method

Answer 1

Hello friend

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3x - 4y - 15 = 0

3x - 4y = 15 .....................( i )

x + y +2 = 0

x + y = -2 ........................( ii )


Multiply by 4 equation (ii) we get

4(x + y = -2)

4x + 4y = - 8 ....................( iii )

Now,we will Add the equation (i ) and ( ii) we get


3x - 4y = 15
4x + 4y = -8
-------------------
7x +0 = 7

7x = 7

x = 7/7

x = 1


x = 1 taking equation ( i ) we get

3x - 4y = 15

3 *1 - 4y = 15

3 - 4y = 15


-4y = 15 - 3

-4y = 12

y = 12/-4

y = -3


hence,x = 1 and y = -3 are the solution of the given equation.

Thanks...

:)

Answer 2

Heya,

Linear equation given =>
3x - 4y - 15 = 0 .... equation 1
x + y + 2 = 0 .... equation 2

Let's take Equation 2 and multiple it by 4, we get..

=> 4(x + y + 2) = 0

=> 4x + 4y + 8 = 0. .... equation 3

Now, add equation 1 and 3

3x - 4y - 15 = 0
4x + 4y + 8 = 0
---------------------
7x - 7 = 0

Further solving this we get,

=> 7x = 7

=> x = 1

Put the value of x in equation 2, we get..

=> x + y + 2 = 0

=> 1 + y + 2 = 0

=> y + 3 = 0

=> y = - 3

So, value of x = 1 and y = -3

Hope this helps....:)