exponents
posted by kate .
I need help with a few problems...
(4^3 x 5^2)(5^4 x 4^5)/ 4^3 x 5^3
and
(2^x+2)  (2^x+5) = 7
please help!:)

Just use the rules for adding and subtracting exponents of the same number, when multiplying or dividing.
(4^3 x 5^2)(5^4 x 4^5)/ (4^3 x 5^3)
= 4^2 x 5^2/(4^3 x 5^3)
= 4^1 x 5^1 = 4/5
Do the second problem the same way