SOLUTION: Factor Completely: 5a^2 - 125 I can not seem to think of how to do this problem with two numbers, can anyone help me out? Thank you

Algebra.Com
Question 70365: Factor Completely:
5a^2 - 125
I can not seem to think of how to do this problem with two numbers, can anyone help me out? Thank you

Answer by funmath(2933)   (Show Source): You can put this solution on YOUR website!
Factor Completely:
5a^2 - 125
First factor out the greatest common factor, 5:
5(a^2)-5(25)
5(a^2-25)
Now you have the diffence of two square , your x=a and y=5

To check, multiply it back out to see if you get back to where you started.
5[a(a-5)+5(a-5)]
5[a(a)+a(-5)+5(a)+5(-5)]
5(a^2-5a+5a-25)
5(a^2-25)
5(a^2)+5(-25)
5a^2-125 We're right!!!!
Happy Calculating!!!!

RELATED QUESTIONS

I need to completely factor out this problem. can anyone help me? 3x^4 + 6x^3 + 5x^3 + (answered by scott8148,MathLover1)
can you please help me with this problem. I do not understand how to do this.... (answered by checkley71,stanbon)
Factor Completely. 27x^2y^3+xy^2 I have xy^2(27xy+1) I think it can be factored... (answered by jim_thompson5910)
Can someone please help me with working out this problem: 8x^2-10x+3 I can not figure it (answered by checkley71)
Use the properties for radical to simplfiy, assume all variables represent positive real... (answered by stanbon,chitra)
I have to completely factor 5x^2-12=-17x. Can someone help me with this... (answered by jim_thompson5910)
On my practice lesson, complex fractions. I am bit overwhelmed with questions with three (answered by jim_thompson5910)
I need to get this from slope-intercept form into standard form. y=3/4x-2/3? I think... (answered by stanbon)
Hello, I have worked this problem out several times. I cannot seem to come up with the... (answered by AssassinXXX)