Question

Resolva os sistemas abaixo

a)
{2x + y =4
{x - y = 2

b)
{x + 2y = 14
{ x + y = 9

c)
{2x - y =20
{x + 3y = 50

d)
{x = 10 - y
{x - y = 2

Answer 1

a) 2x + y = 4
x - y = 2
__________
3x = 6
x = 6/2
x = 3
b) x + 2y = 14
x + y = 9 ( - 2 )
____________
x + 2y = 14
-2x - 2y = - 18.
____________
- x = - 4( - 1 )
x = 4

c) 2x - y = 20 ( 3 )
x + 3y = 50
_____________
6x - 3y = 60
x + 3y = 50
_________
7x = 110
x = 110/7
d) x = 10 - y
x - y = 2
__________
x + y = 10
x - y = 2
_________
2x = 12
x = 12/2
x = 6