Question

Resolver o sistema de equações 3x + y =20 2×+y= 10

Answer 1

$\large\boxed{\begin{array}{l}-\underline{\begin{cases}\rm 3x+y=20\\\rm 2x+y=10\end{cases}}\\\rm 3x-2x=20-10\\\rm x=10\\\rm 2x+y=10\\\rm 2\cdot10+y=10\\\rm 20+y=10\\\rm y=10-20\\\rm y=-10\\\rm S=\{(10,-10)\}\end{array}}$