Question

Помогите пожалуйста ​

Answer 1

$\displaystyle\bf\\\left \{ {{3b=13-20l} \atop {50l=5-2b}} \right. \\\\\\\left \{ {{3b+20l=13} \atop {2b+50l=5}} \right. \\\\\\\left \{ {{3b+20l=13} \atop {b+25l=2,5}} \right. \\\\\\\left \{ {{b=2,5-25l} \atop {3\cdot(2,5-25l)+20l=13}} \right. \\\\\\\left \{ {{b=2,5-25l} \atop {7,5-75l+20l=13}} \right. \\\\\\\left \{ {{b=2,5-25l} \atop {-55l=5,5}} \right. \\\\\\\left \{ {{l=-0,1} \atop {b=2,5-25\cdot(-0,1)}} \right. \\\\\\\left \{ {{l=-0,1} \atop {b=2,5+2,5}} \right.$

$\displaystyle\bf\\\left \{ {{l=-0,1} \atop {b=5}} \right. \\\\\\Otvet \ : \ \Big(5 \ ; \ -0,1\Big)$