Question

x + 3 = 5
(k + 1 )x + 9y = 8k- 1

Answer 1

Answer:

$x + 3y = 5 \\ x = 5 - 3y$

Put x in -

$(k + 1)x + 9y = 8k - 1 \\ \\ (k + 1)(5 - 3y) + 9y = 8k - 1 \\ \\ 5k - 3yk + 5 - 3y + 9y = 8k - 1 \\ \\ 6y - 3yk = 3k - 6 \\ \\ 2y - yk = k - 2 \\ \\ y = \frac{k - 2}{2 - k} = - \frac{k - 2}{k - 2} = - 1$

So,

$x = 5 - 3 \times ( - 1) = 8$