2.1

Question 1

additive inverse

Answer 1

The opposite of a number. A number line can show a sum of 4+(-4).

Question 2

matrix

Answer 2

A rectangular arrangement of numbers in rows and columns. The plural of matrix is matrices.

Question 2

element

Answer 2

You identify the size of the matrix by the number of rows and the number of columns. The matrix above has 3 rows and 2 columns, so it is 3x2 matrix.

Question 3

identity property of addition

Answer 3

For every real number n, n+0=n and 0+n=n

Question 4

inverse property of addition

Answer 4

for every real number n, there is an additive inverse -n such as n+(-n) =0