Factor this expression completely. x^2 - r^2

(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 ?

How are sas and sss used to show that two triangles are congruent?

Given sin28.4=.4756, cos28.4=.8796, and tan28.4=.5407 find the cos of 61.6