How do solve the following linear system?: $4x+3y=1 , -6x-2y=-8$ ?

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Answer 1 · 2018-06-06T17:22:13

the solution is:

$(x,y)-=(2.2,-2.6)$

$4x+3y=1$ ------(1)

$-6x-2y=-8$ ------(2)

If
$a11x+a12y=b11$
$a21x+a22y=b21$

Then,

$x=(b11a22-b21a12)/(a11a22-a21a12)$

$y=(a11b21-a21b11)/(a11a22-a21a12)$

Here,

$a11=4; a12=3; b11=1$

$a21=-6; a22=-2; b21=-8$

Substituting

$x=(1xx(-2)-(-8)xx3)/(4xx(-2)-(-6)xx3)=(-2+24)/(-8+18)=22/10=2.2$

$y=(4xx(-8)-(-6)xx1)/(4xx(-2)-(-6)xx3)=(-32+6)/(-8+18)=-26/10=-2.6$

Check:

$lhs=4x+3y=4xx2.2+3xx(-2.6)=8.8-7.8=1=rhs$

$lhs=-6x-2y=-6xx2.2-2xx(-2.6)=-13.2+5.2=-8=rhs$

Hence,
the solution is:

$(x,y)-=(2.2,-2.6)$

How do solve the following linear system?: 4x+3y=1 , -6x-2y=-8 4x+3y=1 , -6x-2y=-8 ?