Evaluate (1+2/3)*(1+2/5)*(1+2/7)*(1+2/9)
The problem requires you to multiply a series of fractions of the form (1 + 2/n) where n is an odd integer starting from 3 and increasing by 2 each time. Each of these fractions is a term in the series, and you are being asked to calculate the product of the first four terms of this series.
$\left(\right. 1 + \frac{2}{3} \left.\right) \cdot \left(\right. 1 + \frac{2}{5} \left.\right) \cdot \left(\right. 1 + \frac{2}{7} \left.\right) \cdot \left(\right. 1 + \frac{2}{9} \left.\right)$
Express $1$ as a fraction with a denominator that matches the adjacent term. $\left( \frac{3}{3} + \frac{2}{3} \right) \cdot \left( 1 + \frac{2}{5} \right) \cdot \left( 1 + \frac{2}{7} \right) \cdot \left( 1 + \frac{2}{9} \right)$
Combine the numerators over the shared denominator. $\frac{3 + 2}{3} \cdot \left( 1 + \frac{2}{5} \right) \cdot \left( 1 + \frac{2}{7} \right) \cdot \left( 1 + \frac{2}{9} \right)$
Perform the addition in the numerator. $\frac{5}{3} \cdot \left( 1 + \frac{2}{5} \right) \cdot \left( 1 + \frac{2}{7} \right) \cdot \left( 1 + \frac{2}{9} \right)$
Again, express $1$ as a fraction with a suitable denominator. $\frac{5}{3} \cdot \left( \frac{5}{5} + \frac{2}{5} \right) \cdot \left( 1 + \frac{2}{7} \right) \cdot \left( 1 + \frac{2}{9} \right)$
Combine the numerators over the common denominator. $\frac{5}{3} \cdot \frac{5 + 2}{5} \cdot \left( 1 + \frac{2}{7} \right) \cdot \left( 1 + \frac{2}{9} \right)$
Sum the numerators. $\frac{5}{3} \cdot \frac{7}{5} \cdot \left( 1 + \frac{2}{7} \right) \cdot \left( 1 + \frac{2}{9} \right)$
Remove the common factor. $\frac{\cancel{5}}{3} \cdot \frac{7}{\cancel{5}} \cdot \left( 1 + \frac{2}{7} \right) \cdot \left( 1 + \frac{2}{9} \right)$
Simplify the expression. $\frac{1}{3} \cdot 7 \cdot \left( 1 + \frac{2}{7} \right) \cdot \left( 1 + \frac{2}{9} \right)$
Express $1$ as a fraction. $\frac{7}{3} \cdot \left( \frac{7}{7} + \frac{2}{7} \right) \cdot \left( 1 + \frac{2}{9} \right)$
Combine the numerators. $\frac{7}{3} \cdot \frac{7 + 2}{7} \cdot \left( 1 + \frac{2}{9} \right)$
Add the numerators. $\frac{7}{3} \cdot \frac{9}{7} \cdot \left( 1 + \frac{2}{9} \right)$
Remove the common factor. $\frac{\cancel{7}}{3} \cdot \frac{9}{\cancel{7}} \cdot \left( 1 + \frac{2}{9} \right)$
Simplify the expression. $\frac{1}{3} \cdot 9 \cdot \left( 1 + \frac{2}{9} \right)$
Extract $3$ from $9$. $\frac{1}{3} \cdot \left( 3 \cdot 3 \right) \cdot \left( 1 + \frac{2}{9} \right)$
Cancel the common factor. $\frac{1}{\cancel{3}} \cdot \left( \cancel{3} \cdot 3 \right) \cdot \left( 1 + \frac{2}{9} \right)$
Rewrite the simplified expression. $3 \cdot \left( 1 + \frac{2}{9} \right)$
Convert $1$ to a fraction. $3 \cdot \left( \frac{9}{9} + \frac{2}{9} \right)$
Combine the numerators. $3 \cdot \frac{9 + 2}{9}$
Sum the numerators. $3 \cdot \frac{11}{9}$
Factor $3$ from $9$. $3 \cdot \frac{11}{3 \cdot 3}$
Remove the common factor. $\cancel{3} \cdot \frac{11}{\cancel{3} \cdot 3}$
Present the simplified expression. $\frac{11}{3}$
Exact Form: $\frac{11}{3}$ Decimal Form: $3.\overline{6}$ Mixed Number Form: $3 \frac{2}{3}$
To solve the given problem, we used several mathematical concepts and techniques:
Fraction Addition: When adding fractions with the same denominator, we simply add the numerators and keep the denominator the same.
Simplification: We simplified the expression by combining like terms and reducing fractions when possible.
Cancellation: When a number appears in both the numerator and the denominator, it can be canceled out, which is essentially dividing both by that number.
Multiplication of Fractions: To multiply fractions, we multiply the numerators together and the denominators together.
Conversion to Mixed Number: A fraction greater than one can be expressed as a mixed number, which is a whole number plus a proper fraction.
These concepts are fundamental in algebra and are often used in simplifying expressions and solving equations.