Question

Resolva Os sistemas

(com cauculos!)

a) X+Y = 1
X-Y= 3

B) X+Y = 10
X-Y= 30

C) X+Y = 50
X-Y =10

D) X+Y= 12
X-Y=6​

Answer 1

A)

X+Y=1

X-Y=3

2X-0Y=4

2X=4

X=4

2

X=2

2-Y=3

-Y=3-2. (-1)

Y=-3+2

Y=-1

B)

X+Y=10

X-Y=30

2X-0Y=40

2X=40

X=40

2

X=20

20-Y=30

-Y=30-20. (-1)

Y=-30+20

Y=-10

C)

X+Y=50

X-Y=10

2X-OY=60

2X=60

X=60

2

X=30

30+Y=50

Y=50-30

Y=20

D)

X+Y=12

X-Y=6

2X-0Y=18

2X=18

X=18

2

X=9

9+Y=12

Y=12-9

Y=3