Question

resolva os sistemas pelo metodo da adicao

x+2y=7
3x-2y=11

Answer 1

  x + 2y = 7
3x - 2y = 11
4x + 0y = 18 


4x = 18 ---> x = 18/4 ---> x = 9/2


x + 2y = 7 ---> 9/2 + 2y = 7 ; mmc=2--->  9 + 4y = 14 ---> 4y = 14-9 --->

4y = 5 --->  y = 5/4



$S=\left\{ \dfrac{9}{2} ~; \dfrac{5}{4} ~\right\}$