Question

помогите пожалуйста срочно!!!!!10 баллов!!!!​

Answer 1

Пошаговое объяснение:

1. $\left \{ {{4x+3y=2} \atop {x-4y=-9}} \right. = \left \{ {{4(4y-9)+3y=2} \atop {x=4y-9}} \right. =\left \{ {{16y-36+3y=2} \atop {x=4y-9}} \right. = \left \{ {{19y=38} \atop {x=4y-9}} \right. = \left \{ {{y=2} \atop {x=-1}} \right.$

2. a - кол-во домиков

b - кол-во палаток

$\left \{ {{a+b=25} \atop {4a+2b=70}} \right. = \left \{ {{a=25-b} \atop {2b=70-4(25-b)}} \right. = \left \{ {{a=25-b} \atop {b=35-50+2b}} \right. = \left \{ {{a=25-15} \atop {b=15}} \right. = \left \{ {{a=10} \atop {b=15}} \right.$

3.$\left \{ {{3(2x+y)-26=3x-2y} \atop {15-(x-3y)=2x+5}} \right. = \left \{ {{9x+8y=26} \atop {-9x-9y=-30}} \right. ; y=4; \left \{ {{y=4} \atop {9x=6}} \right. = \left \{ {{y=4} \atop {x=\frac{2}{3} }} \right.$

4. $\left \{ {{-9=10k+b} \atop {7=-6k+b}} \right. = \left \{ {{b=-9-10k} \atop {7=-6k-9-10k}} \right. = \left \{ {{b=-9-10k} \atop {k=1 }} \right. = \left \{ {{b=-19} \atop {k=1 }} \right.$

5.$\left \{ {{5x-3y=8} \atop {15x-9y=8}} \right. =\left \{ {{5x-3y=8} \atop {5x-3y=\frac{8}{3} }} \right.$ получается, что 8 = 8/3 ⇒ не имеет