Answer:
3.5
Step-by-step explanation:
Well its easiest to just plug in the answers and see like 2 times 3.5 is 7.
Another way is saying 7 divided by 2 is 3.5
then u check to make sure its the same for all the numbers.
Which it is because 21 divided by 6 is also 3.5 :)
Answer:
Step-by-step explanation:
multiply by 
on each side
add 1 on both sides 
make it equal 0
Factor
answer is 3 and -1
Answer:
Infinite solutions
Step-by-step explanation:
So if simplified it would be
-3x+15=15-3x
Which is basically the same thing if arranged
15-3x=15-3x
-3x+15 can also be 15-3x still the same thing as adding 15 to -3x
So since these are equal anything could be used
like try 0
Both get 15
Try 1
Both get 12
Try legit any number
youll get the same results (I would choose 3 positive easy ones, 0,1,2 and 3 negative ones -1,-2,-3)
