What is the reason for statement 4 in this proof?

What is the factored polynomial 3n^2-48

The times it takes runners to complete a certain marathon are normally distributed with a mean of 4.6 hours and a standard deviation of 1.1 hours. What is the time for a runner with a z-score of - 1.

A pyramid has a height of 10 inches and a base with an area of 21 square inches. Find the volume of the pyramid a.) 35in^3 b.) 210in^3 c.) 105in^3 d.) 70in^3

Michael must drive 120 miles in under 3 hours. If his speed in miles per hour is s, then 120/s < 3. Solve the inequality for s.

Solve the equation - 10 + 1 + 7x = 37

The graph of g (x) is obtained by reflecting the graph of f (x) = 4|x| over the x-axis. Which equation describes g (x) ? A) g (x) = |x-4| B) g (x) = |x+4| C) g (x) = -4|x| D) g (x) = |x|-4

Can you simplify a+2/5a^2+6*3/6

What are the solutions of |6x-1| ≤ 23? Write the solutions as either the union or the intersection of two sets.

The O'Malley family is driving cross-country to see their cousins. So far, they have traveled 275 miles. This is 1/5 of the way to their cousins' house. How far do the O'Malleys live from their cousins?

a sun in a distance galaxy has an estimated mass of 1.61244 * 10 ^32 kg and the earth has a mass of 5.972 * 10^24 kg, how many earths would it take to equal the mass of the sun?