Question

Nicole and Nancy read a total of 18 books this summer. Nancy read 3 more than Nicole. How many did Nicole read?

Answer 1

Assuming Nicole = x, Nancy = y

$x + y = 18 \\ y = x + 3$

Substitute that into
$x + x + 3 = 18 \\ 2x = 15 \\ x = 7.5$

Answer : Nicole read 7.5 books.

Hope this helps. - M

Answer 2

Let the number of books that Nicole read be x.
⇒ Nicole = x

Nancy read 3 more than Nicole
⇒ Nancy = x + 3             

They read a total of 18 books.
⇒ x + ( x+ 3) = 18

Solve for x:
x + ( x + 3) = 18

Remove bracket:
x + x + 3 = 18

Combine like terms:
2x + 3 = 18

Subtract 3 from both sides:
2x = 15

Divide both sides by 2:
x = 7.5

Find the number of books each read:
Nicole = x = 7.5 books
Nancy = x + 3 = 7.5 + 3 = 10.5 books

Answer: Nicole read 7.5 books.