Please can I get some type of help on questions 27 and 29 PLEASE ANYONE

Number 27:Population density refers to the number of people who live in a defined land area (usually square miles or square kilometers). So, if two million people live in ten square miles, the population density is two hundred thousand people per square mile.

Number 29:Your heart beats about 100,000 times in one day. And about 35 million times in a year.And 128 beats in one minute

Step-by-step explanation:

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.