Question

factor each completely. 21) 9mn - 15m - 24n + 40

Explanation:

Step1: Identify the GCF of coefficients

Find GCF of 9, -15, -24, 40. Wait, no, wait the polynomial is \(9mn - 15m - 24n + 40\)? Wait, maybe grouping. Let's group terms: \((9mn - 15m)+(-24n + 40)\)

Step2: Factor out GCF from each group

First group: \(9mn - 15m = 3m(3n - 5)\)
Second group: \(-24n + 40 = -8(3n - 5)\)

Step3: Factor out the common binomial factor

Now we have \(3m(3n - 5)-8(3n - 5)=(3m - 8)(3n - 5)\)

Answer:

\((3m - 8)(3n - 5)\)