• Matéria: Matemática
  • Autor: amandinhapeixer
  • Perguntado 9 anos atrás

Resolver os sistemas pelo método da adição




x=3y
x+2y=10

Respostas

respondido por: ScreenBlack
26
 \left \{ {{x-3y=0\ \ \ \ \ \ \ \ \ \ } \atop {x+2y=10\ \ \times(-1)}} \right.\ \ \Rightarrow\ \   \left \{ {{x-3y=0\ \ } \atop {-x-2y=-10}} \right. \\\\
Somando:\\\\
\left+ \{ {{x-3y=0\ \ } \atop {-x-2y=-10}} \right.\\\\
0x-5y=-10\\\\
Encontrando\ valor\ de\ y:\\\\
-5y=-10\\\\
y=\frac{-10}{-5}\\\\
\boxed{y=2}

Trocando\ o\ valor\ de\ \underline y\ em\ qualquer\ equa\c{c}\~ao\ inicial,\\
 para\ encontrar\ valor\ de\ x:\\\\
x-3y=0\\\\
x-3(2)=0\\\\
x-6=0\\\\
\boxed{x=6}


==Prova\ real==\\\\
Equa\c{c}\~ao\ 1:\\\\
x=3y\\\\
(6)=3(2)\\\\
6=6\\\\\\
Equa\c{c}\~ao\ 2:\\\\
x+2y=10\\\\
(6)+2(2)=10\\\\
6+4=10\\\\
10=10

Bons estudos!
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