Find the sum of the arithmic series: 1. 800 + 790 + … + 20

2. -28+ (-24) + … + 400

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Please help! I have 20 minutes left

The first hexagon is dilated to form the second hexagon select the answers from the drop box menus to correctly complete the statement

Alake near the arctic circle is covered by a 222-meter-thick sheet of ice during the cold winter months. when spring arrives, the warm air gradually melts the ice, causing its thickness to decrease at a constant rate. after 333 weeks, the sheet is only 1.251.251, point, 25 meters thick. let s(t)s(t)s, left parenthesis, t, right parenthesis denote the ice sheet's thickness sss (measured in meters) as a function of time ttt (measured in weeks).

Anyone know? is appreciated! will mark brainliest if correct!