Duncan takes a break from studying and goes to the gym to swim laps. if swimming burns 9.05×105 cal per hour, how many kilojoules does swimming burn in that same amount of time?

What is the value of x in the equation 2(x-4) = 4(2x + 1)?

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?

Angle 1 and 2 are a linear pair. angle 1 equals x-39 and angle 2 equals x+61 . find the measure of each angle