Question

1. (n - 9)(n + 7) =

Explanation:

Step1: Apply FOIL method (First terms)

Multiply first terms of each binomial:
$n \times n = n^2$

Step2: Apply FOIL method (Outer terms)

Multiply outer terms of the binomials:
$n \times 7 = 7n$

Step3: Apply FOIL method (Inner terms)

Multiply inner terms of the binomials:
$-9 \times n = -9n$

Step4: Apply FOIL method (Last terms)

Multiply last terms of each binomial:
$-9 \times 7 = -63$

Step5: Combine all terms and simplify

Combine like terms:
$n^2 + 7n - 9n - 63 = n^2 - 2n - 63$

Answer:

$n^2 - 2n - 63$