In the binary linear equation 5x + 6y = 30, if x and y are opposite to each other, what is x

In the binary linear equation 5x + 6y = 30, if x and y are opposite to each other, what is x

Because X and y are opposite numbers
So y = - X
By substituting y = - x into 5x + 6y = 30, we can get,
5x+6(-x)=30
5x-6x=30
-x=30
x=-30

If x and y are opposite to each other in the quadratic equation 5x-6y = 4, find the value of X and y
I have to do it tonight. After tonight, I have no chance

x. If y is opposite to each other, then
x+y=0
5x+5y=0
It is also known that 5x-6y = 4
By subtracting the two formulas, we get the following result:
11y=-4
y=-4/11
x=4/11

In the bivariate linear equation 5x + 6y = 30, (1) if x and y are equal, then x=___ y=___ (2) If x and y are opposite numbers, then x=___ y=___

When equal, 11x = 30
So x = y = 30 / 11
On the contrary, 5x-6x = 30, x = - 30
y=30