What type of number is -91i

Vhich expression is equivalent to 6(3x + 4)? 9x + 418 x + 2418x + 49x + 10 i might ! i really do hope u see this and answer it

Jorge wants to determine the enlarged dimensions of a digital photo to be used as wallpaper on his computer screen. the original photo was 800 pixels wide by 600 pixels high. the new photo will be 1,260 pixels wide. what will the new height be?

Which expression is equivalent to 64 - 9x^2?