Question

Solve the following simultaneous equation by Elimination method : –

2a + 3b + 4 = 0 , a – 5b = 11​

Answer 1

Answer:

$2a + 3b = - 4 \: \: \: \: (eq1) \\ a - 5b = - 11 \: \: \: \: (eq2) \\ 2(a - 5b = - 11) \\ 2a - 10b = - 22 \: \: \: \: (eq3) \\ eq \: 1 - 3 \\ 2a + 3b = - 4 \\ 2a - 10b = - 22 \\ ( - ) \: \: \: \: \: \: \: \: \: \: ( + ) \: \: \: \: \: \: \: \: \: ( - ) \\ = > 13b = - 26 \\ = > b = - 2 \\ putting \: b = - 2 \: in \: eq2 \\ = > a - 5 \times ( - 2) = - 11 \\ = > a + 10 = - 11 \\ = > a = - 10 - 11 \\ = > a = - 21$