Question

1){5x-3y=0
{15x-2y=55

2){x+y=7
{9y-2x= - 25
Кому не сложно помогите пожалуйста срочно дз
​

Answer 1

1)

$left { {{5x-3y=0} atop {15x-2y=55}} right.$

$left { {{y=frac{5}{3}x } atop {5x-2y=55}} right.$

$left { {{y=frac{5}{3} x} atop {5x-2(frac{5}{3} x)=55$

$left { {{y=frac{5}{3}x } atop {frac{5}{3}x -55=0}} right.$

$left { {{y=frac{5}{3}x } atop {x=33}} right.$

$left { {{y=55} atop {x=33}} right.$

2)

$left { {{x+y=7} atop {9y-2x= - 25}} right.$

$left { {{x+y=7} atop {-2x+9y=-25}} right.$

$left { {{x=-y+7} atop {-2x+9y=-25}} right.$

$left { {{x=-y+7} atop {-2(-y+7)+9y=-25}} right.$

$left { {{x=-y+7} atop {11y+11=0}} right.$

$left { {{x=-y+7} atop {y=-1}} right.$

$left { {{x=8} atop {y=-1}} right.$