Question

factories y2-4 please help me ​

Answer 1

The main concept used here is by applying the important algebraic identity => a²-b².

Step-by-step explanation:

Given:

• y²-4

We need to factorise:

• y²-4

4 can be written as 2×2 = 2²

• y²-2²

On using identity: a²-b² = (a+b)(a-b)

• y²-2² = (y+2)(y-2)

• (y+2)(y-2)

Hence, factorised.

Note: Do you know why we are using identities in these kind of problems? This is so because, the coefficient of y is not given.

Using identities is easier on doing these kind of sums.