If 3x + 5y = 43x+5y=4 and 8y + 6x = 368y+6x=36, what is the value of -yy?

1 Answer

-y=14y=14

Explanation:

3x+5y=43x+5y=4
8y+6x=368y+6x=36
-y=?y=?
3x+5y=4------------(1)3x+5y=4(1)
8y+6x=36------------(2)8y+6x=36(2)
(2)(2) can be simplified as
3x+4y=18-----------(3)3x+4y=18(3)
Subtracting (1) from (3)
4y-5y=18-54y5y=185
-y=14y=14