the sum of the numerator and denominator of a fraction is 3 less than twice the denominator. if the numerator and denominator are decreased by 1, the numerator becomes half the denominator. determine the fraction.
The sum of the numerator and denominator of a fraction is 3 less than twice the denominator. If the numerator and denominator are decreased by 1, the numerator becomes half the denominator. Determine the fraction.
Answer:
To determine the fraction, let’s denote the numerator by ( N ) and the denominator by ( D ). We need to set up two equations based on the information provided.
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Formulate the First Equation:
- The sum of the numerator and the denominator is 3 less than twice the denominator.
This gives us the equation:N + D = 2D - 3 - Simplify this equation:N + D = 2D - 3 \implies N = D - 3 \tag{1}
- The sum of the numerator and the denominator is 3 less than twice the denominator.
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Formulate the Second Equation:
- If the numerator and denominator are decreased by 1, the numerator becomes half the denominator:N - 1 = \frac{1}{2} (D - 1)
- Multiply both sides by 2 to clear the fraction:2(N - 1) = D - 1
- Simplify this equation:2N - 2 = D - 1 \implies 2N - D = 1 \tag{2}
- If the numerator and denominator are decreased by 1, the numerator becomes half the denominator:
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Solve the System of Equations:
- Substitute equation (1) into equation (2):2(D - 3) - D = 1
- Simplify and solve for ( D ):2D - 6 - D = 1 \implies D - 6 = 1 \implies D = 7
- Simplify and solve for ( D ):
- Now, use equation (1) to find ( N ):N = D - 3 \implies N = 7 - 3 \implies N = 4
- Substitute equation (1) into equation (2):
Final Answer:
The fraction is \frac{4}{7}