Anna learns in her science class that the human eye blinks an average of 4,200,000 times a year. what is this number expressed in scientific notation?

Anne is twice as old as bill, and bill is 3 years older than christie. the sum of anne s and christie s ages equal 72. find their age difference.?

An ulcer medication has 300 milligrams in 2 tablets. how many milligrams are in 3 tablets?

What will the graph look like for a system of equations that has no solution? a. the lines will be perpendicular. b. the lines will cross at one point. c. both equations will form the same line. d. the lines will be parallel.