Respuesta :
Answer:
a=-7
Step-by-step explanation:
first we do commutative property of real number
the expression becomes ;
2+(7+a)=
then association property follow-up
(2+7)+a=
7+a=
then we minus 7 to both sides
7-7+a=-7
0+a=-7
a=-7
Answer:
a=-7
Step-by-step explanation:
first we do commutative property of real number
the expression becomes ;
2+(7+a)=
then association property follow-up
(2+7)+a=
7+a=
then we minus 7 to both sides
7-7+a=-7
0+a=-7
a=-7