$x+2y = 11 \ldots$ Eq.(1)

$3x+y=13 \implies y=13-3x \ldots$ Eq.(2)

Substitute Eq.(2) into Eq.(1):

$x+2(13-3x) = 11\\ x+26-6x = 11\\ 15=5x\\ x=3$

Substitute to find $y$ :

$y=13-3(3) = 4$

Therefore, $x+y = 3+4 = \boxed{7}$

2 ×+4 y=22 add

3*×+y =13

5 ×+5 y=35

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__5*(x+y)=35---- ------x+y=35/5=7.

Equation 1:

$x$ + 2 $y$ = 11

= $x$ = 11 - 2 $y$

Equation 2:

3 $x$ + $y$ = 13

= 3 $x$ = 13 - $y$

Simultaneous Equations:

Eq 1. $x$ = 11 - 2 $y$

Eq 2. 3 $x$ = 13 - $y$

Eq 2. 6 $x$ = 26 - 2 $y$

Step 1. Cancel out the - 2 $y$ 's

Step 2. Subtract 6 $x$ from $x$ = - 5 $x$

Step 3. Subtract 26 from 11 = - 15

-5 $x$ = -15

$x$ = 3

$y$ = 4

$x$ + $y$ = 7