Answer:
5x+5y=15
Step-by-step explanation:
Answer:
pretty sure it's irrational numbers
Answer:
I think it would be -0.416 but I'm not real sure so make sure before using my answer! :3 Have a great day!
Answer:
The number is 2
Step-by-step explanation:
Twice a number (z) = 2*z = 2z
Twice a number (z) added to 21 = 2z + 21
9 times the number added to 7 = 9z + 7
9z + 7 = 2z + 21
Subtract 2z form both sides
9z - 2z + 7 = 21
7z + 7 = 21
Subtract 7 from both sides
7z = 21 - 7
7z = 14
Divide both sides by 7
z = 14/7
z = 2
Commutative says you can add or multiply in any order
basically goes like this
a+b=b+a or
ab=ba
so what we need is something where the order change, nothing else
first one: (4+3)+x=(3+4)+x, the order changed, correct
2nd
ab=ba, this is not addition
3rd
r+(s+t)=(r+s)+t this is associative property
4th
n+0=n
this is zero addition property
answer is first one
