Question

Solve the system by graphing. y=x−22 x+y=1

Answer 1

Answer:

C

Step-by-step explanation:

Answer 2

$1.\\y=x-2\\\\for\ x=0\to y=0-2=-2\to(0;-2)\\for\ x=2\to y=2-2=0\to(2;\ 0)\\\\2x+y=1\to y=1-2x\\\\for\ x=0\to y=1-2\cdot0=1\to(0;\ 1)\\for\ x=1\to y=1-2\cdot1=-1\to(1;-1)\\\\Look\ at\ the\ picture.\\\\Answer:\boxed{(1;-1)}\to\fbox{A.}$


$x^2+x=12\\x^2+x-12=0\\\\a=1;\ b=1;\ c=-12\\\Delta=b^2-4ac\\if\ \Delta \ \textgreater \ 0\ then\ x_1=\dfrac{-b-\sqrt\Delta}{2a}\ and\ x_2=\dfrac{-b+\sqrt\Delta}{2a}\\\\\Delta=1^2-4\cdot1\cdot(-12)=1+48=49 \ \textgreater \ 0\\\sqrt\Delta=\sqrt{49}=7\\\\x_1=\dfrac{-1-7}{2\cdot1}=\dfrac{-8}{2}=-4\\\\x_2=\dfrac{-1+7}{2\cdot1}=\dfrac{6}{2}=3\\\\Answer:\boxed{-4;\ 3}\to\fbox{A.}$


$-14+x^2=5x\to x^2-5x-14=0\\\\x^2-7x+2x-14=0\\x(x-7)+2(x-7)=0\\(x-7)(x+2)=0\iff x-7=0\ or\ x+2=0\\x=7\ or\ x=-2\\\\Answer:\boxed{-2;\ 7}\to\fbox{C.}$