Factor completely. 5a2 – 125?

Answer 1

take 5 common
that equals
5(a^2-25)[25 can also be written as 5^2
a^2-25 is in the form of a^2-b^2
=(a+b)(a-b)
let a be a and b be 5
=5(a+5)(a-5)

Answer 2

5(x - 5)(x + 5)

Here's how:

You have 5x2 -125.

Stick a 0x in the middle. 5x2 +0x -125 You now have a trinomial.

Think: What factors of -625 (you multiply 5 by -125) add up to zero? 25 and -25.

Rewrite the equation: 5x2 +25x -25x -125.

Pull out the greatest common factor from the 5x2 and the 25x. This is 5x. Next, pull out the greatest common factor from -25x and -125. This is -25.

Rewrite: 5x(x+5) -25(x+5)

Notice you have (x+5) twice. Write (x+5) as the first part of your equation. The second comes from the two outside numbers, 5x and -25. It will be written as (5x-25).

You now have: (5x-25)(x+5)

You can still factor. The greatest common factor of 5 and -25 is five. Pull that out.

Your answer: 5(x-5)(x+5)

Answer 3

First, factor out a 5..

5(a^2-25)

Then factor the (a^2-25)

5 (a+5)(a-5)

Remember that when you have a term that has the format (x^2-(b^2)), its factors will always be (x+b)(X-b)

Answer 4

125 = 5^3 8x*3 = (2x)^3 Apply the formula: a^3 - b^3 = (a - b)(a^2 + ab + b^2) Where: a = 5, then a^2 = 5^2 = 25 and 5^3 = 125 and b = 2x then (2x)^2 = 4x^2 and (2x)^3 = 8x^3 we can re-write as: 125 - 8x^3 = 5^3 - (2x)^3 = (5 - 2x)(25 + 5*2x + 4x^2) = (5 - 2x)(25 + 10x + 4x^2) is the answer. Good Luck!

Answer 5

5a^2-125
= 5(a^2 - 25)
=5(a+5)(a-5)

Answer 6

5(a^2 -25)
5(a-5)(a+5)

Answer 7

Look for something in common between the two terms. Divide by that.Then recognise that what you have is the difference of two squares. You should know what to do with one of those.

Answer 8

5(a^2-25)
5(a-5)(a+5)===Answer

Answer 9

Why can't you do it?