6x + 5y = 4

10x + 9y = 0

make the first equation into only one variable so that you can substitute that one variable into the second equation and get your answer.

6X equals 4 - 5y

now substitute

x equals 2 by 3 - 5x 6y

10 * 2 by 3 - 5 / 6y

now multiply and simplify the second equation

20 / 3 - 5 6 y y equals 0