What is the justification for the step taken from line 2 to line 3?
3x+9-7X=X+10+X
-4x+9=2x+10
-6x+9= 10
-6x=1
1
X=-
6
W
O the subtraction property of equality
O the multiplication property of equality
O combining like terms on one side of the equation
O the distributive property
