Question

algm me ajuda scrrr​

Answer 1

a)  x = 3 + y

2x + y = 9

2 . (3 + y) + y = 9

6 + 2y + y = 9

6 + 3y = 9  

3y = 9 - 6

y = 3/3

y = 1

x = 3 + y

x = 3 + 1

x = 4

b) x = 3y

x + 2y = 10

(3y) + 2y = 10

5y = 10

y = 10/5

y = 2

x = 3y

x = 3*2

x = 6

c) y = 10 - x

2x - y = 8

2(y-10) - y = 8

2y - 20 - y = 8

y - 20 = 8

y = 8 + 20

y = 28

x + y = 10

x + 28 = 10

x = 10 - 28

x = - 18

d) x = 2y

3x + 5y = 55

3(2y) + 5y = 55

6y + 5y = 55

11y = 55

y = 55/11

y = 5

x = 2y

x = 2*5

x = 10