Explain why 2.15 and -2.15 are opposites.
They are the same distance from 0 on a number line.
http://img.sparknotes.com/figures/5/50ca5e784bb7e4242910d5b8a571d103/number_line.gif
explain why 2.15 and -2.15 are opposites
Graph each number and its opposite on a number
To understand why 2.15 and -2.15 are opposites, we need to first understand what the concept of "opposites" means in mathematics.
In mathematics, the concept of opposites refers to numbers that are equal in magnitude but have different signs. For example, 2 and -2 are opposites because they have the same absolute value (magnitude) of 2, but differ in sign. This applies to any number, including decimals like 2.15.
To see why 2.15 and -2.15 are opposites, we can examine their magnitude and sign:
1. Magnitude: The absolute value of 2.15 is 2.15, as it is the distance of the number from zero on the number line. Similarly, the absolute value of -2.15 is also 2.15, as the distance from zero is the same.
2. Sign: The sign of a number indicates whether it is positive or negative. In the case of 2.15, it is positive because it has no negative sign in front of it. On the other hand, -2.15 is negative because it has a negative sign ("-") in front of it.
Since 2.15 and -2.15 have the same magnitude (absolute value) but have opposite signs, they are considered as opposites in mathematics.