How do you solve the following system: $x+y=4 , 3x + 4y = 11$ ?

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Answer 1 · 2018-07-07T19:00:41

$x=5$ , $y=-1$

Given that

$x+y=4\ .........(1)$

$3x+4y=11\ .........(2)$

Multiplying (1) by $3$ & subtracting from (2) as follows

$3x+4y-3(x+y)=11-3\times 4$

$y=-1$

setting $y=-1$ in (1), we get

$x=4-y=4-(-1)=5$

hence, the solution is $x=5$ & $y=-1$

How do you solve the following system: x+y=4 , 3x + 4y = 11 x+y=4 , 3x + 4y = 11 ?