SOLUTION: Multiply the expressions, and simplify. {{{(7x^(-1)y^3)}}}{{{""*""}}}{{{(-10xy^(-5))}}} Can someone please help?

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Multiply the expressions, and simplify. {{{(7x^(-1)y^3)}}}{{{""*""}}}{{{(-10xy^(-5))}}} Can someone please help?      Log On


   



Question 373651: Multiply the expressions, and simplify.
%287x%5E%28-1%29y%5E3%29%22%22%2A%22%22%28-10xy%5E%28-5%29%29

Can someone please help?

Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!
%287x%5E%28-1%29y%5E3%29%22%22%2A%22%22%28-10xy%5E%28-5%29%29
Notice that the x on the right has the understood exponent 1:

%287x%5E%28-1%29y%5E3%29%22%22%2A%22%22%28-10x%5E1y%5E%28-5%29%29

1. We multiply the coefficient 7 by the 
coefficient -10 and get -70.  

2. We add the exponent of the x on the left, -1, and the 
   exponent of x on the right %22%22%2B1,

3. We add the exponent of the y on the left, 3, and the 
   exponent of y on the right -5,

-70x%5E%28-1%2B1%29y%5E%283-5%29


4. We complete the addition of the exponents:

-70x%5E0y%5E%28-2%29

5.  We replace the x%5E0 by %281%29

-70%281%29y%5E%28-2%29

6. -70 time 1 is just -70

-70y%5E%28-2%29

7. To make a negative exponent positive you move the factor from
   the numerator to the denominator and change the sign
   of the exponent to positive:

8. %22%22-%22%2270%2Fy%5E2

That's it.

Edwin