Final answer:
To factorise the expression 8x^2 - 20, we can rewrite it as 4(2x^2 - 5). The quadratic trinomial 2x^2 - 5 is not factorable further using integer values.
Step-by-step explanation:
To factorise the expression 8x^2 - 20, we can take out the greatest common factor.
In this case, the greatest common factor is 4, so we can rewrite the expression as 4(2x^2 - 5).
Now, we need to factorise the quadratic trinomial inside the parentheses.
The quadratic trinomial 2x^2 - 5 is not factorable further using integer values.
So, the factorised form of the expression 8x^2 - 20 is 4(2x^2 - 5).