98 points, just tryna give some away

Atrain leaves little? rock, arkansas, and travels north at 90 kilometers per hour. another train leaves at the same time and travels south at 80 kilometers per hour. how long will it take before they are 680 kilometers? apart?

What is the perimeter of an isosceles triangle with each leg measuring 2x+3 and the base measuring 6x-2?

Point j (-4,-6) and point k (4,4) are located on a coordinate grid. which measurement is closest to the distance between point j and point k in units