Question

Resolva os sistemas:

a. { x + y = -1
{ 3x - y =3

b. { 5x - y = 4
{ 2x - y = -5

c. { x + 2y = 7
{ 4x - y = 10

d. { 3x - 2y = 7
{ x + 3y = -16

Agradeço a quem puder me ajudar aa

Answer 1

Resposta:Bom trabalho

Explicação passo-a-passo:$a) \left \{ {{x+y=-1} \atop{3x-y = 3}} \right. = \left \{ {{y=-1-x} \atop {-----}} \right. = \left \{ {{-------} \atop {3x-(-1-x)=3}} \right.  =\left \{ {{-----} \atop {3x+1+x=3}} \right.=\left \{ {{---} \atop {4x=2}} \right. =\left \{ {{--} \atop {x=\frac{2}{4} }} \right.=\left \{ {{y=-1-\frac{2}{4} } \atop {---}} \right.  =\left \{ {{y=\frac{-4-2}{4} } \atop {----}} \right. =\left \{ {{y=-\frac{6}{4} } \atop {x=\frac{2}{4} }}=\left \{ {{y=-\frac{3}{2} } \atop {x=\frac{1}{2} }} \right.$

$\left \{ {{5x-y=4}\atop {2x-y=-5}} \right.=\left \{ {{-y=4-5x} \atop {-------}} \right. =\left \{ {{y=-4+5x} \atop {------}} \right.=\left \{ {{----} \atop {2x-(-4+5x)=-5}} \right.  =\left \{ {{-----} \atop {2x+4-5x=-5}} \right. =\left \{ {{----} \atop {-3x=-9}} \right. =\left \{ {{-----} \atop {x=3}} \right.=\left \{ {{y=-4+5*3} \atop {----}} \right.=\left \{ {{y=11} \atop {x=3}} \right.$

$c) \left \{ {{x+2y=7} \atop {4x-y=10}} \right.=\left \{ {{x=7-2y} \atop {---}} \right. =\left \{ {{----} \atop {4*(7-2y)-y=10}} \right. =\left \{ {{----} \atop {28-8y-y=10}} \right. =\left \{ {{-----} \atop {-9y=-18}} \right. =\left \{ {{----} \atop {y=2}} \right. =\left \{ {{x=7-2*2} \atop {---}} \right. =\left \{ {{x=3} \atop {y=2}} \right.$

$d) \left \{ {{3x-2y=7} \atop {x+3y=-16}} \right. =\left \{ {{-----} \atop {x=-16-3y}} \right. =\left \{ {{3*(-16-3y)-2y=7} \atop {----}} \right. =\left \{ {{-48-9y-2y=7} \atop {----}} \right. =\left \{ {{-11y=55} \atop {-----}} \right. =\left \{ {{y=-5} \atop {----}} \right. =\left \{ {{----} \atop {x=-16-3*(-5)}} \right. =\left \{ {{----} \atop {x=-16+15}} \right=\left \{ {{y=-5} \atop {x=-1}} \right. .$