Question

a) {
x − y = 5
x + 3y = 9
b) {
3x − 2y = 6
x − 3y = 2
c) {
x + y = 4
2x + y = 7

d) {
x − y = 1
− x + 2y = 3
e) {
x = 3y
x − 2y = 3
f) {
2x + y = − 3
x + y = − 1

Answer 1

Resposta:

a) {x=5+y

x+3y=9

5+y+3y=9

y=1

x=5+1 = 6

(x,y)=(6,1)

{6-1=5

6+3×1=9

{5=5

9=9

(x,y)=(6,1)

b) {3x-2y=6

x=2+3y

3(2+3y)-2y=6

y=0

x=2+3×0

x=2

(x,y)=(2,0)

{3×2-2×0=6

2-3×0=2

{6=6

2=2

(x,y)=(2,0)

c) {y=4-x

2x+y=7

2x+4-x=7

x=3

y=4-3= 1

(x,y)=(3,1)

{3+1=4

2×3+1=7

{4=4

7=7

(x,y)=(3,1)

d) {x=1+y

-x+2y=3

-(1+y)+2y=3

y=4

x=1+4= 5

(x,y)=(5,4)

{5-4=1

-5+2×4=3

{1=1

3=3

(x,y)=(5,4)

e) 3y-2y=3

y=3

x=3×3=9

(x,y)=(9,3)

{9=3×3

9-2×3=3

{9=9

3=3

(x,y)=(9,3)

f) {x+y=-3

y=-1-x

2x-1-x=-3

x=-2

y=-1-(-2)= +1

(x,y)=(-2,1)

{2×(-2)+1=-3

-2+1=-1

{-3=-3

-1=-1

(x,y)=(-2,1)

Explicação passo-a-passo:

Espero ter ajudado, bons estudos! ^^