Saturday, August 24, 2013

`2x - y + 2 = 0, 4x + y - 5 = 0` Solve the system by the method of substitution.

Solve equation [2] for the variable  y 
 


`y = -4x + 5`


Plug this in for variable  y  in equation [1]


`2x - (-4x+5) = -2`
`6x = 3`

Solve equation [1] for the variable  x 


`6x = 3`

`x = 1/2`

By now we know this much :


`x = 1/2`
`y = -4x+5`

Use the  x  value to solve for  y 


`y = -4(1/2)+5 = 3`

Solution is `(1/2,3)`

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