Find the value of z such that 0.7698 of the area lies between -z and z

An equation representing lyle’s hedge-trimming business is a = 12n - 300 where a is the amount of profit or loss in dollars and n is the number of hedges trimmed. how would the graph of lyle’s business change if the equation a = 10n - 300 represented his business? the graph would be flatter. the graph would be steeper. the graph would start closer to the origin. the graph would start lower on the y-axis.

How to solve a simultaneous equation involved with fractions?

What is the value of x in the following equation? -3x-2=2x+8