Final answer:
To convert 2.123(23) into a rational number in standard form, multiply both sides by 100, subtract the original equation from the new equation, and then finally simplify and divide to find the answer.
Step-by-step explanation:
To convert the decimal 2.123(23) into a rational number in its standard form, we need to express it as a fraction.
Let x = 2.123(23).
Multiply both sides of the equation by 100 to eliminate the repeating decimal: 100x = 212.323(23).
Subtract the original equation from the new equation: 100x - x = 212.323(23) - 2.123(23).
Simplify to get 99x = 210.2.
Divide both sides of the equation by 99: x = 210.2/99.
This is the rational number in its standard form.
Learn more about Converting a decimal into a rational number in standard form