Answer:
I will ASSUME X = x
x² + 2bx - 4bx - 8b²
x² - 2bx - 8b²
[tex]\\\\\\-8b^2-2bx+x^2[/tex]
Step-by-step explanation:
[tex](x+2b)(x-4b)\\=(x+2b)(x+(-4b)\\=(x)(x)+(x)(-4b)+(2b)(x)+(2b)(-4b)\\\\x^2-4bx+2bx-8b^2\\\\-8b^2-2bx+x^2[/tex]