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