Hello,
I suppose equations are:
x+y=3 (1)
x+2y=9 (2)
(2)-(1)==>y=6
(1)==>x=3-6
x=-3, y=6
Sol={(-3,6)}
Answer:
Step-by-step explanation:
The expression is
x^2 - 4
This is a quadratic expression.
To find the solution, we will equate the the expression to zero. It becomes
x^2 - 4 = 0
Add 4 to the left hand side of the equation and the right hand side of the equation. It becomes.
x^2 - 4 + 4 = 0 + 4
x^2 = 4
Take square root of the right hand side of the equation and left hand side of the equation. It becomes
√x^2 = √4
x = ± 2
x = 2 or x = - 2