Question

The left and right page numbers of an open book are two consecutive integers whose sum is 519.Find these page numbers.

Answer 1

Solution

Let x be the left number, then x+1 the right number. According to the condition,the sum of two numbers is 519, hence

$$x+(x+1)=519.$$

Solve this equation

$$x+x+1=519;$$

$$2x+1=519;$$

$$2x=518;$$

$$x=259;$$

$$x+1=260$$

Answer:

The number of the left page is 259 and the number of the right page is 260.