PRACTICE TEST HELP

maddy*1

New member
Joined
Feb 18, 2006
Messages
2
I've got a maths test monday and this is a question in the practice test please help me out :

8a to the power of 4 b to the power of 6 x 9a to the power of 3 b to the power of 7

hope it makes sense
 
Hello, maddy*1!

\(\displaystyle \L(8a^4b^6)(9a^3b^7)\)
Sort the factors like this: \(\displaystyle \L\,8\,\cdot9\,\cdot\,a^4\,\cdot\,a^3\,\cdot\, b^6\,\cdot\,b^7\)

\(\displaystyle \;\;\)(Do it "in your head"; you don't have to write this out.)


Multiply the coefficients (normal arithmetic): \(\displaystyle \L\,8\,\times\,9\:=\:72\)

and multiply the variables (Use the Multiplication Rule for exponents:

\(\displaystyle \L\;\;\;a^4\,\cdot\,a^3\:=\:a^{(4+3)}\:=\:a^7\;\;\;\;\;b^6\,\cdot\,b^7\:=\:b^{(6+7)}\:=\:b^{13}\)


\(\displaystyle \text{Answer: }\L\;72a^{^7}b^{^{13}}\)
 
Top