.HELP ME PLEASEE IM IN AN EXA Billy was asked to solve 3^5∙3^4. He got 9^20. What error did he make? *

a) When he multiplies exponents, he is supposed to add the base and the exponent
b) When he multiplies exponents, he is supposed to multiply the base and keep the exponents
c) When he multiplies exponents, he is supposed to keep the base and add the exponents if the base is the same
d) None of the above

Someone answer this asap for gabriella uses the current exchange rate to write the function, h(x), where x is the number of u. s. dollars and h(x) is the number of euros, the european union currency. she checks the rate and finds that h(100) = 7.5. which statement best describes what h(100) = 75 signifies? a. gabriella averages 7.5 u. s. dollars for every 100 euros. b. gabriella averages 100 u. s. dollars for every 25 euros. c. gabriella can exchange 75 u. s. dollars for 100 euros. d. gabriella can exchange 100 u. s. dollars for 75 euros.