Question

помогите пожалуйста очень срочно

Answer 1

Объяснение:

a)

$\left \{ {{\frac{y}{4}-\frac{x}{5}=8\ |:3 } \atop {\frac{x}{15}+\frac{y}{12} =0 }} \right. \ \ \ \ \left \{ {{\frac{y}{12}=\frac{8}{3}+\frac{x}{15}\ |*12 } \atop {\frac{x}{15}+\frac{8}{3} +\frac{x}{15} =0}} \right. \ \ \ \ \left \{ {{y=32+\frac{4x}{5} } \atop {\frac{2x}{15}=-\frac{8}{3} \ |*\frac{15}{2} }} \right.\ \ \ \ \left \{ {{y=32+\frac{4*(-20)}{5} } \atop {x=-20}} \right. \ \ \ \ \left \{ {{y=16} \atop {x=-20}} \right. .$

Ответ: x=-20      y=16.

б)

$\left \{ {{2*(2a-b)+3*(2a+b)=32} \atop {5*(2a-b)-2*(2a+b)=4}} \right. \ \ \ \ \left \{ {{4a-2b+6a+3b=32} \atop {10a-5b-4a-2b=4}} \right.\ \ \ \ \left \{ {{10a+b=32} \atop {6a-7b=4}} \right. \ \ \ \ \left \{ {{b=32-10a} \atop {6a-7*(32-10a)=4}} \right. \\\left \{ {{b=32-10a} \atop {6a-224+70a=4}} \right.\ \ \ \ \left \{ {{b=32-10a} \atop {76a=228\ |:76}} \right. \ \ \ \ \left \{ {{b=2} \atop {a=3}} \right. .$

Ответ: a=3      b=2.