Question

РЕШИТЕ ДАЮ 35 БАЛЛОВ!!!

Answer 1

$1)\ \ f(x)=\left\{\begin{array}{l}-x^2\ ,\ esli\ -2\leq x\leq 1\ ,\\-2x+3\ ,\ esli\ x>1\end{array}\right\\\\f(-2)=-(-2)^2=-4\\\\f(1)=-1^2=-1\\\\f(2)=-2\cdot 2+3=-4+3=-1$

 

$2)\ \ \left\{\begin{array}{l}5x+\dfrac{1}{2}\, y=-3\ | \cdot 2\\-4x-\dfrac{3}{4}\, y=1\ |\cdot 4 \end{array}\right\ \ \left\{\begin{array}{l}10x+y=-6\ |\cdot 3\\-16x-3y=4\end{array}\right\ \oplus \ \left\{\begin{array}{l}14x=-14\\3y=-16x-4\end{array}\right$

$\left\{\begin{array}{l}x=-1\\3y=12\end{array}\right\ \ \left\{\begin{array}{l}x=-1\\y=4\end{array}\right\ \ \ \ Otvet:\ \ (-1;4)\ .$

$3)\ \ \left\{\begin{array}{l}\dfrac{2x+3y}{4}=\dfrac{3x+4y}{7}\\\dfrac{5x-6y}{10}=-\dfrac{4x-12}{2}\end{array}\right\ \ \left\{\begin{array}{l}7(2x+3y)=4(3x+4y)\\5x-6y=-5(4x-12)\end{array}\right\\\\\\\left\{\begin{array}{l}14x-12x=16y-21y\\3x+20x=6y+60\end{array}\right\ \ \left\{\begin{array}{l}2x=-5y\\25x=6y+60\end{array}\right\ \ \left\{\begin{array}{l}x=-2,5y\\6y=25x-60\end{array}\right$

$\left\{\begin{array}{l}x=-2,5y\\6y=62,5y-60\end{array}\right\ \ \left\{\begin{array}{l}x=-2,5y\\56,5y=60\end{array}\right\ \ \left\{\begin{array}{l}x=-\dfrac{60}{22,6}=-2\dfrac{74}{113}\\y=\dfrac{60}{56,5}=1\dfrac{7}{113} \end{array}\right$