Question

Halley's Comet appears in the sky once every 75 years it last appeared in 1986 two students wrote Expressions to find out which years after 1986, will appear.Julian says 75× Casey says 1986+75xWhose expression is correct and why?A) Neither expression is correct, because the correct expression is 75 + 1986x.B)Both expressions are correct because both show that appears every 75 years.D) Julian's expression is correct, because it shows that the comet appears every 75 years. The hear it last appeared it doesn't matter.

Answer 1

The expression that will tell us the years after 1986 is Casey's:

$1986+75x$

The reason being: every 75 years the comet will do another "pass by" and we will have to add 75 each new time.

So, the option is B) since each can be used to determine the values, but Casey's is more "practical".