Question

Resolva:

$<var>\left \{ {{2x+4y=5} \atop {2x+3y=2}} \right.</var>$

Answer 1

   
        2x + 4y = 5 (1)
        2x + 3x = 2(-1)

        2x + 4y =  5 
       - 2x - 3x = - 2
                 y = 3

          2x = 5 - 4y ==> 2x = 5 - 4(3)==> 2x = 5-12==> 2x= - 7 ==> x = - 7/2

Answer 2

y=5-2x
2x+3.(5-2x)=2
2x-6x=2-15
-4x=-13 .(-1)
+4x=+13
x=$\frac{13}{4}$
y=5-2.$\frac{13}{4}$=$\frac{21}{4}$
($\frac{13}{4}, \frac{21}{4}$)