Question

Why the value of k so that the pair of linear equation x minus 2 y is equal to 3 and 3 x + y is equal 5 has a unique solution unique solution?

Answer 1

$x - 2y = 3 \\ ( + ) 6x + 2y = 10 \\ \\ = 7x = 13 \\ x = 13 \div 7 = something \\ y = 10 - 3x$