What is a-2b, where a=4-2i and b=3+2i?

Could someone with number 1 and 2

G. how many different 6-letter arrangements can be formed using the letters in the word absent, if each letter is used only once? a. 6 b. 36 c. 720 d. 46,656

The function below is written in vertex form or intercept form. rewrite them in standard form and show your work. y = -3(x-2)(x-4)