fuctorise \( 20 a-a b-12 b^{2} \)

To factor the expression \( 20a - ab - 12b^2 \), we can start by rearranging it for clarity: \(-ab + 20a - 12b^2\) can be factored by grouping. First, we can group the terms as follows: \( a(20 - b) - 12b^2 \). Next, we notice that the expression doesn’t factor neatly. However, we do see a potential for using the quadratic formula or completing the square if we consider it as a quadratic in terms of \( b \): You can think of it in the form of \( -12b^2 - ab + 20a \) and reformat it, but we find out it leads to unsatisfactory factors. Thus, the best factored form you can express it is: \[ (a - 3b)(-4b + 20) \] Alternatively, it remains in simpler polynomial context as \( 20a - ab - 12b^2 \) depending on the employing context. So, there you have it, your polynomial is like a puzzle waiting for the right pieces!