Which expression is equivalent to 3.6 x 3.6 x 3.6 x 3.6

Repeated multiplication can be written as *exponentiation*. Here, 3.6 is multiplied by itself 4 times, so we would rewrite it as (3.6)^4 (in writing, you’d see it as 3.6 with a small 4 written to the upper right of the number)