if 12 g of a radioactive substance are present initally and 8 yr layer only 6 g remain, how much of the substance will be present after 17 yr

Given the function f(x) = log base 4(x+8) , find the value of f^-1(2)

Line cd passes through points c(1, 3) and d(4, –3). if the equation of the line is written in slope-intercept form, y = mx + b, what is the value of b? –5 –2 1 5

Figure abcde is a regular pentagon. segment ae is located at a (2, 1) and e (4, 1). what is the perimeter of abcde? 4 units 6 units 8 units 10 units