How do you simplify (2a-1)^2?

Question

How do you simplify (2a-1)^2

Answer 1

4a^2-4a+1
Use the FOIL method (multiply First terms, then Outside terms, then Inside terms, then Last terms).

So you have:
(2a-1)*(2a-1)
(2a*2a)+(2a*-1)+(-1*2a)+(-1*-1)
4a^2-2a-2a+1
4a^2-4a+1

Answer 2

FOIL
4a^2-4a+1

Answer 3

use the formula (a-b)^2= a^2 - 2ab + b^2
therefore, (2a-1)^2 = (2a)^2 - 2(2a)(1) + (1)^2
= 4a^2-4a+1

Answer 4

(2a)^2 - 2(2a)(1) + 1^2

= 4a^2 - 4a +1