math

[tishypoo]

I need help with fractions and need it explained to me so I understand. Fractions totally confuse me. One problems is
7 5/12 + 2 1/3. I know the common denominator would be 12 but then what do you do?

 

[tkhunny]

By 7 5/12, do you mean $\displaystyle 7\frac{5}{12}$ or equivalently 7 + (5/12)?

Can you convert to an "Improper Fraction"? That would be a great place to start.

 

[soroban]

Hello, tishypoo!

I hope you know how to add two fractions . . .

$\displaystyle 7\tfrac{5}{12} + 2\tfrac{1}{3}$

$\displaystyle \text{We have: }\;\left(7 + \tfrac{5}{12}\right) + \left(2 + \tfrac{1}{3}\right) \;=\;9 + \left(\tfrac{5}{12} + \tfrac{1}{3}\right)$

To add the two fractions, we need a common denomiator: 12

Convert both fractions so they have a denominator of 12.

. . $\displaystyle \text{The first fraction is already: }\:\frac{5}{12}$

. . $\displaystyle \text{Multiply the second fraction by }\tfrac{4}{4}\!:\;\;\frac{1}{3}\cdot\frac{4}{4} \:=\:\frac{4}{12}$

$\displaystyle \text{So we have: }\:\frac{5}{12} + \frac{4}{12} \;=\;\frac{9}{12} \;=\;\frac{3}{4}$


. . $\displaystyle \text{Answer: }\;9\tfrac{3}{4}$