a.
A variable is an unknown number or value represented by a letter
c.
A variable represents a change in value
b.
A variable always represents the total amount
d.
A variable is always represented by the letter x
Please select the best answer from the choices provided
A variable is an unknown number or value represented by a letter. If there was an equation x+2=19, then x would be the variable, because it is a letter representing an unknown value hope this helps:))