Pls help asap with the question above

(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 ?

For f(x)=2x+3 and g(x)=x^2- 8 find (f+g) (x)

Which system of linear inequalities is represented by the graph?