Answer: 
Step-by-step explanation:
The first step to solve the exercise is to make the conversion from meters to centimeters.
Since
, then the dimensions of the wood board in centimeters are:

Now, you must find the Greatest Common Factor (GCF). The steps are:
- Descompose 100 and 60 into their prime factors:

- Multiply the commons with the lowest exponents:

Therefore, the side lenght of each square must be:

I think the answer is: -4.25
Answer: A. 20 is the answer.
Step-by-step explanation:
x+40 = 3x
or, 40 = 3x-x
or, 2x = 40
or, x = 40/2
so, x = 20