Find the sum of the sigma notation

Element x decays radioactively with a half life of 8 minutes. if there are 450 grams of element x, how long, to the nearest tenth of a minute, would it take the element to decay to 37 grams?

Find the area and perimeter of each composite figure. use 3.14 for π. round your answer to the nearest tenth. a square and a right triangle share a common side. image long description a 3-meter by 0.5-meter rectangle has triangles attached like wings to the 3-meter sides. the other two sides of both triangles measure 2.5 meters. the height of each triangle is 2 meters. a 6-inch by 4-inch rectangle has 2 half-circles attached like wings to the 6-inch sides. the radius of each half-circle is 3 inches. find the surface area and volume of each figure. use 3.14 for π. round your answer to the nearest tenth. a right circular cylinder has a base radius of 6 yards and a height of 20 yards. a rectangular prism has a base that is 9 centimeters long and 7 centimeters wide. the height is 2 centimeters. a rectangular prism has a base that measures 11 millimeters by 11 millimeters. the height is 11 millimeters.

To describe a sequence of transformations that maps triangle abc onto triangle a"b"c", a student starts with a reflection over the x-axis.how should the student complete the sequence of transformations to map triangle abc onto triangle a"b"c"? plz