Scientific Notation is a style of equation where a number that is too big to be practical (i.e. a number that has many zeros after it) is shifted around until it is between 1 and 10.
For example, a number like 986000000 would be 9.86*10^8 in scientific notation. Scientific notation is recognizable by the (term)*10^n, where 'n' is however many places the decimal moves.
2 + 2 = 2 * 2 = 2^2 = sqrt(16)
7.5 * 0.75 I presume?
Put it into fractions. 15/2 * 3/4
15/2 = 30/4
30/4 * 3/4 = 90/16
80/16 = 5
5 + 10/16 = 5 + 5/8
Putting it back into decimal form (as given) then the answer is 5.625
@Anon: Thanks, I'm not the best at conversions like that.
Anon below me is correct.
Remember PEMDAS
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction
25 - (3^2 + 2 * 5)
Do what's in the parenthesis first.
3^2 + 2 * 5
Do exponents next.
3^2 = 9
Multiplication/Division after that.
2 * 5 = 10
Finally, addition.
9 + 10 = 19
Now, we have finished up what it inside the parenthesis. We can now look at the whole problem.
25 - 19 = 6
Your final answer is 6
Depends on what I'm being asked about.
Just as an example, an architect has to measure all of the dimensions for a room, and a lot of fashion is actually loosely related to math (Golden Ratio, anybody?)
Think of how many times 2 needs to be multiplied in order to get eight.
2 x 2 = 4
4 x 2 = 8
Therefore, since 3 '2's were used, x = 3
First, make all the denominators equal.
23+y3=33
That way, since all of the denominators are equal, they can all be canceled out. This makes the equation:
2+y=3
Subtract 2 to isolate 'y'.
y=1
Final answer.
+1006 
