Question

pf me ajuda nessa tarefa

Answer 1

a) x + y = 9
x - y = 5

2x = 14
x = 14/2
x = 7

b) 4x - y = 8
x + y = 7
5x = 15
x = 15/5
x = 3

c) x - 3y = 5 (m2)
2x + 4y = 0 
2x - 6y = 10
2x + 4y = 0
-2y = 10
-y = 10/2
-y = 5  (m-1)
y = -5


e) 2x + 3y = 2 (m3)
4x - 9y = -1
6x + 9y = 6
4x - 9y = -1
10x = 5
x = 5/10
x = 0,5