Some help on some math problems please?

Question

can u please help w/ some math? oh and can u show how u did it so i understand? thx.
btw ^ means exponent/ to the power of. i think..

1. 225/(-3)(-5) = ?

2. -2 x -6 + 4 x -5^2 = ?

3. 2/5 divided by - 1/2 = ?

4. 3/4 / (- 3/7) = ?

thats all! thanks and remember-10 points =)

Answer 1

give me a minute.

All right, just remember PEMDAS. (parentheses, exponents, multiplication/division (left to right), addition/subtraction (left to right). So with that in mind:

1. first step is 225/-3 which is -75.
Then it is -75 * -5 which is 375. Final answer is 375.

Wait, it is either that way or this way, because I don't understand how you have written this. If I did it the way you have it written, it would in fact be 375. Because in order of operations, you would do the division because it is the first thing on the left. And you are only using the parentheses as dividers of the (-) symbol. But (and I'm no mindreader), you might have meant the () around the -3 and -5 to mean multiply them, which in that case you would multiply them together first. Then you would have 225 / 15, which is 15. Apply whichever method to your problem after you see which one it is.

2. first step is exponent. Rewrite as -2 * -6 + 4 * 25.
Then multiplication: 12 +100.
final answer is 112.

Again, I'm not sure how it is written is how it is supposed to be. The way I solved the problem is that the x's you used were supposed to represent multiplying (times), not as an algebraic symbol. If it is supposed to mean simple x, then the answer would be different.

3. Find common denominator, which is 10. Convert to 4/10 divided by -5/10.
flip second and multiply. Now it is 4/10 * -10/5. This is -40/50. Reduce and now a -4/5. Final answer is negative 4/5.

4. Same thing, find cd. would be 28. 21/28 divided by -12/28. So that is same as 21/28 * -28/12, which is
-588/336. Reduce to -7/4. Final answer is -7/4.

Answer 2

1) I am GUESSING you mean

225/[(-3)(-5)], simplify denominator
= 225/15, note it's positive, factor numerator
=[15*15]/15
= 15.

2) -2 x -6 + 4 x -5^2 = ? , rearrange
- 5 x^2 -2x + 4x -6 =, add like terms
- 5 x^2 + 2x -6.


3. 2/5 divided by - 1/2 = ?

You mean (2/5) divided by (-1/2). This is equal to

(2/5) * (2/-1), not the flip
= 4 /(-5) = - 4/5

4. 3/4 / (- 3/7) = ?

Same thing here. This is

(3/4) * (7/-3), flip
= (3*7) / (4*(-3))

= (3*7)/( 4* (-1)*(3)), see why?

= 7/-4, after you cancel 3.

Answer 3

1. 225/(-3)(-5) = 225/15 = 15

2. -2 x -6 + 4 x -5^2 = 12 +4(-100) = -388

3. 2/5 divided by - 1/2 = 2/5 X -2/1 = - 4/5

4. 3/4 / (- 3/7) = 3/4 X -7/3 = -7/4 (the 3's cancel nicely)

Answer 4

Uh....Windows XP (and advanced versions) carry a calculator within it's programs. Might want to make use of it.