Question

3a + b = 7
2a + 3b = 7
ayuda

Answer 1

Explicación paso a paso:

{3a + b = 7} * -3

2a + 3b = 7

-9a -3b = -21

2a + 3b = 7

-7a = -14

a = 2

3(2) + b = 7

6 + b = 7

b = 1