Question

12x + 5y = 10
- 10x - minha 5y =14

(Método de adição )

Answer 1

$\left\{\begin{matrix}12x+5y=10 &(1)\\\\-10x-5y=14&(2)\end{matrix}\right.\\\\\\\\(1)+(2)=(12x+(-10x))+5y\hspace{-10}\diagup-5y\hspace{-10}\diagup=10+14\\\\\\=12x-10x=24\\\\\\=2x=24\\\\\\x=\dfrac{24}{2}\\\\\\x=12\\\\\\\text{Substituindo x em (1):}\\\\\\12\cdot 12+5y=10\\\\\\144+5y=10\\\\\\5y=10-144\\\\\\5y=-134\\\\\\y= \dfrac{-134}{5}\\\\\\ y=-\dfrac{134}{5}\\\\\\\left\{\begin{matrix}x=12\\\\y=-\dfrac{134}{5} &\end{matrix}\right$