Use the discriminant to find out.
b^2 - 4ac
a = 2
b = 1
c = - 1
1^2 - 4(2)(- 1)
1 + 8 = 9 > 1
so, there are two real roots to this equation. ( two real solutions )
There is no solution since the equation is inconsistent.
x = 0 and y = 4
The equation does not have a solution.
It has one double solution.
No. The equation describes a straight line and the coordinates of any one of the infinitely many points on the line is a solution.
-5
The coordinates of every one of the infinitely many points on the line defined by the equation is a solution.
Without an indication of the equals sign, this is not an equation.
Not sure what you mean; that equation certainly has a solution.
It is a linear equation in x. The equation has the solution x = 0.
x = 19
One equation with two unknowns usually does not have a solution.