Question

resolva os sistemas

a- 2x + y = 18
x - y= -3
___________

b- x + y= 9
3x - y = -1
_____________

c- x + y = 11
2x + y = 15

____________

d- 2x - y = 4
x - y = -1





com contas ​

Answer 1

Resposta:

A) 2 x + y = 18

x - y = 3 (-1) multiplica por menos 1

2x + y = 18

- x + y = - 3

3x = 21

x = 7 logo y = 4

________________________________

B) 2x = 133

x = 133/3

x= 67

________________________________

C) x + y = 11 (×4). 4x 4y = 44

2x + y = 15. 2x -4y= 10

6x= 54 x =

54/ 6 x = 9

________________________________

D) 2x - y = 4

x- y = 1

5x = 5

x=1