Question

? + ? = 12


+ +


? - ? = 4

= =
17 12

Answer 1

let ? be x ,y,z and a
as x+y=12
z-a= 4

x+ z= 17.
and y+a =12

y +a =12 and x+y=12.
therefore a=x.
z+x=17.
z+a=17. equation one
z-a=4. equation 2.

adding eq 1 and eq 2.
z+a=17
z-a=4
+______
2z =21
z= 21/2.
then x = 17-21/2.
17-10.5=6.5
a= x= 6.5

y = 12-x
=12-6.5= 5.5.


[text]<i><b>Verification...[/text]

1.x + y = 12
6.5+5.5 =12

2.z-a=4
10.5-6.5= 4.

3.x+z=17
6.5+10.5 = 17..

4. y+a =12
5.5 +6.5= 12..


hence proved that my answer is correct..

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it's best answer and correct also...
I'm sure please mark it as brainlist...

Answer 2

x+y=12
x-y=4
2x=16
x=8
x+y=12
8+y=12
y=4
therefore x=8
y=4