The greatest common factor is 28.
The factors of 56 are: 1, 2, 4, 7, 8, 14, 28, 56
The factors of 84 are: 1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42, 84
Then the greatest common factor is 28.
Answer to Problem 1: 5√3
Answer to Problem 2: 21√5
Answer:
this question is not complete. need another equation
Step-by-step explanation:
give another equation then I can solve

Answer:
(-5, 3)
Step-by-step explanation:
Elimination seems like the best method to use here.
x+y=-2
x-y=-8
---------
2x=-10
Divide everything by two
x=-5
Now plug it back into one of the original equations,
-5+y=-2
Add 5 to everything
y=3