Help me plz with the math test

Which matrix can be multiplied to the left of a vector matrix to get a new vector matrix ?

Find the slope of the line below . enter your answer as a fraction or decimal. use a slash mark ( / ) as the fraction bar if necessary

Which statement is true about a number and its additive inverse? a. their product is always one. b. their sum is always one. c. they are always reciprocals of each other. d. their sum is always zero.