A sofa regularly sells for $840. The sales price is$714. Find the percent decrease of the sale price from the regular price

(a) calculate the molarity of a solution that contains 0.0345 mol nh4cl in 400 ml of solution. (b) how many moles of hno3 are present in 35.0 ml of a 2.20 m solution of nitric acid? (c) how many milliliters of 1.50 m koh solution are needed to supply 0.125 mil of koh ?

Tom drove 206 miles in 3.9 hours. estimate his average speed.

Is (root2 -2)^2 rational or irrational. show the steps and answer fast