Which of the following best represents a function?

For something to be a function, the input (x value) can only have one output (y value). If an x value has more than one y value, it is not a function.

A.) When x = 1, it has 5 y values. This is not a function

B.) -2 and -1 have two y values. This is not a function

C.) 1 and 2 have two y values. This is not a function

D.) Each input has only one output. This is a function. (Inputs can share the same outputs)

Your answer is D

23,598 because  513 x 40 = ( 500 x 40 ) + ( 10 X 40 ) + ( 3 x 40 ) = 20 000 + 400 + 120 = 20,520 and another partial product is  513 x 6 = ( 500 x 6 ) + ( 10 x 6 ) + ( 3 x 6 ) = 3 000 + 60 + 18 = 3,078. so 20,520 + 3,078 = 23,598