Tutor profile: Bhavini T.

Expand the following equation: (3x+4)(2x-7)

So remember that it's "First, outside, inside, last" (FOIL) First: 3x x 2x =6x^2 Outside: 3x x -7= -21x Inside: 4 x 2x= 8x Last: 4 x -7= -28 Put them all together to make an equation: 6x^2 -21x + 8x -28 And to simplify: 6x^2 -13x -28

Why is fluorine so reactive?

Fluorine is a small atom with one full electron shell and one that is almost full. It has space in it's second shell for 1 more electron. Atoms like to have full electron shells and smaller atoms have the electrons closer to their nucleus, making it easier to steal electrons from other atoms and it's easier for them to hold onto their own electrons. Since fluorine is both small and only has one electron left to fill its outer shell, it can easily steal electrons from other atoms. Fluorine is so reactive that it will only be found as "fluoride" in nature, which is the form it takes when it already has that extra electron.

Why do you get diarrhea when you have lactase deficiency?

Lactose is a type of sugar found in dairy products and in the intestines it is broken down by the enzyme "Lactase" into glucose and galactose, which are then small enough to be absorbed into the blood stream. If you don't have lactase, lactose will sit in the intestines because the molecule is too big to be absorbed into the blood stream, so it will draw out water from the body. This extra water in the intestines will then lead to diarrhea.