# Thread: I need help factoring (in R and in C) please...!?

1. ## I need help factoring (in R and in C) please...!?

I need help factoring (in R and in C) please...!?
I need help factoring the following please...

1. Factor completely (in R), if possible:

5x^2 - 625

2. Factor completely (in R), if possible:

5x^2 + 625

3. Factor completely (in C), if possible:

5x^2 + 625

4. Factor completely (in R), if possible:

5x^3 + 625

5. Factor completely (in C), if possible:

5x^3 + 625

6. Factor completely (in R), if possible:

5x^3 - 625

Thanks so much for your help! :<)

2. First factor them with 5. Then use addition or subtraction of squares or cubes.

$\displaystyle a^2 - b^2 = (a-b)(a+b)$

$\displaystyle a^3 + b^3 = (a+b)(a^2-ab+b^2)$

$\displaystyle a^3 - b^3 = (a-b)(a^2+ab+b^2)$

3. and $\displaystyle a^2+b^2 = (a+bi)(a-bi)$