Question

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

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

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

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

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

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

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

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

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