What is the total number of digits required in numbering the pages of a book, which has 1,724 pages?

Step-by-step explanation:

we know that

When numbering the pages of a book, which has 1,724 pages, we need:

9 one-digit numbers (from 1 - 9)

90 two-digit numbers (from 10 - 99)

900 three-digit numbers (from 100 - 999)

725 four-digit numbers (from 1,000 - 1,724)

Multiply each value by the number of digits

so

the solution is 12x-6y

because linear equations are a lot simpler than quadratics equations, and linear equations formula is a lot easier to memorize. that's why i think they're harder.