Question

Sistemas lineares: x-y=16 x+y=2 alguem pode me ajudar?

Answer 1

x-y=16 ----------> x=16+y
x+y=2

16+y+y=2
2y=2-16
2y=-14
y=-14/2
y=-7

x=16+y
x=16+(-7)
x=9

Answer 2

$\begin{Bmatrix}x-y=16~~\bigcirc \hspace{-9}{i}\\\\x+y=2~~~~\bigcirc\hspace{-11}{ii}\end.\\\\\\\textit{ Vamos encontrar uma express\~ao para x a partir de}~\bigcirc\hspace{-9}i\\\\~~x-y=16\\\\~~x=\underline{16+y}\\\\\textit{ Agora vamos substituir x em}~\bigcirc\hspace{-11}ii\\\\~~x+y=2\\\\~~16+y+y=2\\\\~~16+2y=2\\\\~~2y=-14\\\\~~y=-\dfrac{14}{2}\\\\~~\fbox{ y=-7 }$

$\textit{~Para descobrir x basta substituir o valor encontrado para y em}\\\textit{~uma das equa\c{c}\~oes. Vou substituir em}~\bigcirc\hspace{-9}i\\\\~~x-y=16\\\\~~x-(-7)=16\\\\~~x+7=16\\\\~~\fbox{ x=9 }\\\\\\\textit{~Solu\c{c}\~ao~para~o~sistema:}~~\begin{Bmatrix}x=9\\\\~~y=-7\end.$