Question

Пожалуйста с решением

Answer 1

а) {х=5у

{ 2х-7у=6

2*5у-7у=6

3у=6

у=2

х=5*2=10

ответ:(10;2)

б){у=2-3х

{5х+4у=-6

5х+4(2-3х)=-6

5х+8-12х=-6

-7х=-14

х=2

у=2-3*2=-4

ответ:(2;-4)

в){6х-у=4

{3х+5у=13

{-у=4-6х

{3х+5у=13

{у=6х-4

{3х+5у=13

3х+5(6х-4)=13

3х+30х-20=13

33х=33

х=1

у=6*1-4=2

ответ:(1;2)

Answer 2

Ответ:

Объяснение:

a)

$\left \{ {{x=5y} \atop {2x-7y=6}} \right.$

$\left \{ {{x=5y} \atop {10y-7y=6}} \right.$

$\left \{ {{x=5y} \atop {3y=6}} \right.$

$\left \{ {{x=5y} \atop {y=2}} \right.$

x=5*2=10

(10;2)

б)

$\left \{ {{y=2-3x} \atop {5x+4y=-6}} \right.$

$\left \{ {{y=2-3x} \atop {5x+4(2-3x)=-6}} \right.$

$\left \{ {{y=2-3x} \atop {5x+8-12x=-6}} \right.$

$\left \{ {{y=2-3x} \atop {-7x=-14}} \right.$

$\left \{ {{y=2-3x} \atop {x=2}} \right.$

y=2-3*2=-2-6=-4

(2;-4)

в)

$\left \{ {{6x-y=4} \atop {3x+5y=13}} \right.$

$\left \{ {{y=6x-4} \atop {3x+5y=13}} \right.$

$\left \{ {{y=6x-4} \atop {3x+5(6x-4)=13}} \right.$

$\left \{ {{y=6x-4} \atop {3x+30x-20=13}} \right.$

$\left \{ {{y=6x-4} \atop {33x=33}} \right.$

$\left \{ {{y=6x-4} \atop {x=1}} \right.$

y=6*1-4=2

(1;2)