Given:
The statements and reasons to solve an equation.
To find:
The missing reason.
Solution:
If a, b and c are three real number, then
Associative property of addition : [tex](a+b)+c=a+(b+c)[/tex]
Commutative property of addition : [tex]a+b=b+a[/tex]
Multiplicative property of equality : [tex]a=b\Leftrightarrow ca=cb[/tex]
Distributive property of multiplication over addition : [tex]a(b+c)=ab+ac[/tex]
In the given step, [tex](x+-3)+3[/tex] is written as [tex]x+(-3+3)[/tex].
It means, only parenthesis are changed, which is possible by Associative property of addition.
So, the missing reason is Associative property of addition.
Therefore, the correct option is A.
