What does multiplying a number by -1 mean?

The interior angles formed by the side of a hexagon have measures of them up to 720° what is the measure of angle a

Select the correct answer from each drop-down menu. a system of equations and its solution are given below. system a complete the sentences to explain what steps were followed to obtain the system of equations below. system b to get system b, the equation in system a was replaced by the sum of that equation and times the equation. the solution to system b the same as the solution to system a.]

The price of a car has been reduced from $19,000 to $11,590. what is the percentage decrease of the price of the car?