Find all complex numbers $z$ such that $z^4 = -4.$ Note: All solutions should be expressed in the form $a+bi$, where $a$ and $b$ are real numbers.

Please help fast! I appreciate your help :)

(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 ?

Based on the diagram, match the trigonometric ratios with the corresponding ratios of the sides of the triangle. tiles : cosb sinb tanb sincposs matches: c/b b/a b/c c/a

Order the measurements from the least to the greatest. 2,720 ml , 24.91 l , 0.0268 kl