I'll mark you as the brainiest if you get this correct thx xxx This homework is due tomorrow thx sm for your help Please show you working

700

Step-by-step explanation:

3x + x = 80

4x = 80

x= 20

there are 60 fictional books and 20 nonfiction.

since each fiction book is 10, the total cost of 60 is 600.

and nonfiction books are 5 each because half the price. so 20*5 = 100

Helen will receive 700.

answer: 4  

the square root of 16 is 4. it is a very simple mathematic concept. a square root when a number multiplied by itself will result in a number. here, the number 16 comes when 4 is multiplied by 4. hence the square root of 16 is 4. you can always figure out a square root by the inverse operation of squaring.