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Which expression is equivalent to (3^2)^-2 a.-81 b.-12 c.1/81 d.1/12

The ph level of a blueberry is 3.1 what is the hydrogen-ion concentration [h+] for the blueberry

Aaron invested a total of $4,100, some in an account earning 8% simple interest, and the rest in an account earning 5% simple interest. how much did he invest in each account if after one year he earned $211 in interest? select one: a. $200 at 8%, $3,900 at 5% b. $3,200 at 8%, $900 at 5% c. $900 at 8%, $3,200 at 5% d. $3,900 at 8%, $200 at 5%