Which quantity could be used in the blank to make the equation true? 3x + x + = 8x

a) 3x b) 4x c) 5x d) x2

If the perimeter of the square equals the perimeter of the regular pentagon. each side of a pentagon is 16cm long. how long is each side of the square?

The length of time it takes to find a parking space at 9 a.m. follows a normal distribution with a mean of 5 minutes and a standard deviation of 2 minutes. find the probability that it takes at least 8 minutes to find a parking space. (round your answer to four decimal places.)

Anew obstacle course is home to several new types of challenging obstacles. one such obstacle is traversing a 15-stair staircase. to make it more challenging, the stairs are not uniformly spaced. rather, the vertical space between consecutive stairs for the first 10 stairs is 113 feet and the vertical space for the last 5 stairs is 134 feet. what is the total vertical distance traveled ascending and descending the entire 15-stair staircase?