Convert the mixed numbers into fractions.
[tex]5 \frac{1}{4} [/tex]
[tex]5 * 4 = 20[/tex]
[tex]20 + 1 = 21[/tex]
[tex]5 \frac{1}{4} = \frac{21}{4}[/tex]
[tex]1 \frac{7}{8} [/tex]
[tex]1 * 8 = 8[/tex]
[tex]8 + 7 = 15[/tex]
[tex]1 \frac{7}{8} = \frac{15}{8} [/tex]
Because both fractions have different denominators, we have to change one fraction so that its denominator will match. We will take 21/4 and multiply both the numerator and denominator by 2 so that it will match the denominator of 15/8:
[tex] \frac{21}{4} * \frac{2}{2} = \frac{42}{8} [/tex]
Now we can subtract 42/8 by 15/8:
[tex]\frac{42}{8} - \frac{15}{8} = \frac{27}{8}[/tex]
Convert the fraction back into a mixed number:
[tex]27 / 8 = 3 R3 = 3 \frac{3}{8} [/tex]
The piece of iron weighted 3 and three-eighths pounds more than the piece of aluminum.
