Question

five minus twenty x square​

Answer 1

20x2−5=5(4x2−1) = 5(2x−1)(2x+1)

Explanation:

So we have 20x2−5=5(4x2−1); dividing thru by 5.

5(4x2−1)

And 4x2−1 is the difference between 2 squares, 2x and 1.

(4x2−1) = (2x−1)(2x+1)

Putting it all together:

20x2−5=5(2x−1)(2x+1)

So there are roots at ±12.

Answer 2

20x2−5=5(4x2−1) = 5(2x−1)(2x+1)

Explanation:

So we have 20x2−5=5(4x2−1); dividing thru by 5.

5(4x2−1)

And 4x2−1 is the difference between 2 squares, 2x and 1.

(4x2−1) = (2x−1)(2x+1)

Putting it all together:

20x2−5=5(2x−1)(2x+1)

So there are roots at ±12.