Question

5) Aplicando o método da adição, a solução do sistema abaixo é: jx-y=-5 (2x + 3y = 10 a) ( )S=((-1,4)} b) ( ) S = ((-2,2)} c) ( ) 5 =((2,3)} d) ( S = ((-5, 10}}

Answer 1

$\boxed{\begin{array}{l}\begin{cases}\sf x-y=-5\\\sf 2x+3y=10\end{cases}\\\\\begin{cases}\sf x-y=-5\cdot(3)\\\sf 2x+3y=10\end{cases}\\\\+\underline{\begin{cases}\sf3x-\diagdown\!\!\!\!\!\!3y=-15\\\sf 2x+\diagdown\!\!\!\!\!3y=10\end{cases}}\\\sf5x=-5\\\sf x=-\dfrac{5}{5}\\\\\sf x=-1\\\sf x-y=-5\\\sf -1-y=-5\\\sf y=5-1\\\sf y=4\\\sf S=\{(-1,4)\}\\\huge\boxed{\boxed{\boxed{\boxed{\sf\maltese~alternativa~ a}}}} \end{array}}$