# Posts by sandrine

Total # Posts: 7

**chemistry**

How many joules of heat are required to completely covert 95.0 grams of water to steam?

**chemistry**

i have difficulty in this question. any help would be appreciated. 1) What pH corresponds to each of the following: (a) (H+)=0.35M,(b)(OH^-)= 6.0*10^-6M. (d)(H+)= 2.5*10^-8M?

**science**

why eating carrots is important for good vision?

**biology**

why eating carrots is important for good vision?

**Algebra**

I'm cubing the binomial (3x+2)^3. THe answer is 54x^2 according to my book, however I got different answers each time. Once I got 74x^2. How do I get 54x^2? I know the order of operations but when I followed it, the boo answer was not the one I got.

**Algebra**

How come when you find the square of the binomial (2x-5y)^2, the answer is 4x^2-20xy+25y^2 (according to my book)? I would think that the middle term, 2(2x-5y) would be 4x-10y, but my book says it is -20xy. But I thought you 2x and 5y were separate terms so you can't ...

**Algebra**

I multiplyed x^2-2x+2 times x^2+2x+2. The book suggested the order this be done in as: x^2(x^2-2x+2) then 2x(x^2-2x+2) then 2(x^2-2x+2), with the result being x^4+4. However, I wondered if this could be done in reverse. So I multiplyed x^2(x^2+2x+2), then -2x(x^2+2x=2) then 2(...