How many centimeters are there in 1.23 x 10 to the negative 6th power

Find the greatest common factor of the polynomial: 10x^5+15x^4-25x^3 10x^5 x^3 5x^3 5

What are the solutions of the system? solve by graphing. y = -x^2 -6x - 7 y = 2

Atourist boat is used for sightseeing in a nearby river. the boat travels 2.4 miles downstream and in the same amount of time, it travels 1.8 miles upstream. if the boat travels at an average speed of 21 miles per hour in the still water, find the current of the river.