ANSWER
[tex](1-7x)(1+9x) =- 63 {x}^{2} + 2x + 1[/tex]
EXPLANATION
The given product is (1-7x)(1+9x).
Expand using the distributive property.
[tex](1-7x)(1+9x) = 1(1 + 9x) - 7x(1 + 9x)[/tex]
[tex](1-7x)(1+9x) = 1 + 9x - 7x - 63 {x}^{2}[/tex]
Simplify to obtain:
[tex](1-7x)(1+9x) = 1 + 2x - 63 {x}^{2}[/tex]
You can rewrite in standard form to get,
[tex](1-7x)(1+9x) =- 63 {x}^{2} + 2x + 1[/tex]
