1. miababygirl1987

I am suposse to smplify it |dw:1330211637642:dw|

2. gjakova

|dw:1330211747318:dw|

3. gjakova

|dw:1330211833532:dw|

4. miababygirl1987

and (3xy^2) (-7x^2y^4) I am suppose to multipy this and I have no cluse how to

5. AccessDenied

Property of Multiplying exponents of the same base: \[ a^{m} a^{n} = a^{m + n} \] -7 * 3 = -21 x * x^2 = x^(1+2) = x^3 y^2 * y^4 = y^(2+4) = y^6

6. miababygirl1987

because I got 21x^3y^6 but I dont think it is right

7. cathyangs

multiply the like parts: 3 goes with -7, x with x, and y with y.

8. cathyangs

you missed the negative is all. :D

9. miababygirl1987

how do I Write 625 in exponential notation

10. cathyangs

you mean in scientific notation?

11. cathyangs

or in prime factorization?

12. miababygirl1987

no it says expontial notation

13. AccessDenied

Exponential notation is scientific notation, I believe. a * 10^b, where 1 <= a <= 9, and a,b are integers

14. cathyangs

...ok, I'm guessing that's the same as scientific. The first part has to be a number between 1 and 9, which in your case is 6.25. Because you have to multiply 6.25 by 100 to get 625, it's 6.25*100, or 6.25*10^2 in scientific notation.

15. AccessDenied

oops, I should say, a is not integer! I forgot! D:

16. cathyangs

alternately, you can think of it as: from 6.25 to 625, you have to move the decimal back 2 places, so it's 10^2.

17. cathyangs

well, a can be an integer, but doesn't have to.

18. miababygirl1987

how do you work this kind of problem ? |dw:1330212185975:dw|

19. cathyangs

(a/b)^x = (a^x)/(b^x). You can apply this to that equation.

20. miababygirl1987

because I got 9/16 is that right ?

21. cathyangs

try again.

22. miababygirl1987

I got this time 6/16

23. cathyangs

...? Make sure you do the inner parentheses first.

24. miababygirl1987

now I got 1/2

25. cathyangs

that's right. gj!