Factorise completely. $24a^2b + 12ab^2 - ab$ Answer ... $mn - 18 - 9m + 2n$ Answer ... Expand and simplify $(-2x+3q)(x-2q)$. Answer ...

1. Identify the common factor in all three terms and factor it out.

$24a^2b+12ab^2-ab=ab(24a+12b-1)$

1. Group the four terms into two pairs with common factors.

$mn - 18 - 9m + 2n$

Rearrange and group:

$mn - 9m + 2n - 18$

2. Factorise each group and extract the common binomial factor.

$mn - 9m + 2n - 18$

$= m(n-9) + 2(n-9)$

$= (m+2)(n-9)$

1. Expand the product of the two binomials term by term.

$(-2x+3q)(x-2q)$

$=(-2x)(x)+(-2x)(-2q)+(3q)(x)+(3q)(-2q)$

$=-2x^2+4qx+3qx-6q^2$

2. Collect like terms to simplify the expression.

$-2x^2+4qx+3qx-6q^2$

$=-2x^2+7qx-6q^2$