Simplify this expression: 54 + 31 + 7n by the power of 2 - n by the power of 2

10 ! a train starts from grand city and travels toward belleville 388 miles away. at the same time, a train starts from belleville and runs at the rate of 47 miles per hour toward grand city. they pass each other 4 hours later. find the rate of the train from grand city.

Solve each quadratic equation by factoring and using the zero product property. 14x - 49 = x^2

Which of the following pair(s) of circles have las a common external tangent? select all that apply. a and b a and c b and c