Question

Resolva o sistema: {3x+y=9
{2x+3y=13

Answer 1

3x + y = 9
2x + 3y = 13

y = 9 - 3x

2x + 3. ( 9 - 3x ) = 13
2x +27 - 9x = 13
2x - 9x = 13 - 27
- 7x = -14
x = 14/7
x = 2

3.(2) + y = 9
6 + y = 9
y = 9 - 6
y = 3

3.( 2) + 3 = 9 
6 + 3 = 9
9 = 9

x = 2
y = 3