Question

será que alguem pode me ajudar nessa questão

Answer 1

a){x+y=11
{x-y=3

x+y=11
x=11-y

x-y=3
11-y-y=3
-2y=3-11
-2y=-8
y=4

x=11-y
x=11-4
x=7

b){x+y=6
{2x+y=4

x+y=6
x=6-y

2x+y=4
2.(6-y)+y=4
12-2y+y=4
-y=4-12
-y=-8
y=8

x=6-y
x=6-8
y=-2

c){3x+y=5
{2x+y=4

3x+y=5
y=5-3x

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

y=5-3x
y=5-3.5
y=5-15
y=-10

e){x-y=6
{x+y=-8
2x=-14
x=7

x-y=6
7-y=6
-y=6-7
-y=-1
y=1

e){x=5-3y
{2x-y=-4

2x-y=-4
2.(5-3y)-y=4
10-6y-y=4
-7y=4-10
-7y=-6
y=6/7

x=5-3y
x=5-3.(6/7)
x=5-18/7
x=35-18
x=17

f){x-3=-y
{3x+2=y+3

x-3=-y
x=-y+3

3x+2=y+3
3.(-y+3)+2=y+3
-3y+9+2=y+3
-3y-y=3-11
-4y=-8
y=2

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

Espero ter ajudado!