
The multiple zero is x = -4.
The multiplicity is 2 because there are two values of x.
3x + 6 = 12
First operation was subtraction (subtracting 6 to leave 3x alone)
Second operation was division (Dividing 3 from 3x to isolare x)
3x + 6 = 12
3x + 6 -(6) = 12 - 6
3x = 6

=

3 and 3 cancels out
x = 2
X = -1, y = 5. Hope this helps