Question

How I can resolve this problem

Answer 1

3x^2 - 75 =
First factor out the 3
3 (x^2 - 25) =

Now we have a difference of squares

= 3(x + 5)(x -5)

Answer 2

Well, the first step is to ALWAYS see if there is a GCF. In this case there is. It is 3. 

Now we must take out that 3 gcf and put it outside the parentheses like you're used to doing. 

3(  )

By taking three out, we are basically dividing everything by 3. 

3x^2/3 Would leave us with just x^2 or x squared. 

3(x^2)

Now we will divide -75 by 3. We get -25. So let's add that in the parentheses. 

3(x^2 - 25) 

That should be the final answer!