tentukan hasil dari A.2/15-1/2+3/10 B.3/7+4/21-13/14 C.4 2/5-1 1/3+2 3/4 D.10 1/4+1 2/3+20 7/8 E.2,25+25%+1 1/2

Tentukan hasil dari

• a. 2/15 - 1/2 + 3/10
• b. 3/7 + 4/21 - 13/14
• c. 4 2/5 - 1 1/3 + 2 3/4
• d. 10 1/4 + 1 2/3 + 20 7/8
• e. 2,25 + 25% + 1 1/2

Pembahasan :

• a. 2/15 - 1/2 + 3/10

[tex]\displaystyle \frac{2}{15} - \frac{1}{2} + \frac{3}{10}[/tex]

= [tex]\displaystyle \frac{4}{30} - \frac{15}{30} + \frac{9}{30}[/tex]

= [tex]\displaystyle\frac{-11}{30} + \frac{9}{30}[/tex]

= [tex]\displaystyle -\frac{2}{30}[/tex]

= [tex]\displaystyle -\frac{1}{15}[/tex]

• b. 3/7 + 4/21 - 13/14

[tex]\displaystyle \frac{3}{7} + \frac{4}{21} - \frac{13}{14}[/tex]

= [tex]\displaystyle \frac{18}{42} + \frac{8}{42} - \frac{39}{42}[/tex]

= [tex]\displaystyle \frac{26}{42} - \frac{39}{42}[/tex]

= [tex]\displaystyle-\frac{13}{42}[/tex]

• c. 4 2/5 - 1 1/3 + 2 3/4

[tex]\displaystyle 4\frac{2}{5} - 1\frac{1}{3} + 2\frac{3}{4}[/tex]

= [tex]\displaystyle 4\frac{24}{60} - 1\frac{20}{60} + 2\frac{45}{60}[/tex]

= [tex](4 - 1 + 2) + (\displaystyle \frac{24-20+45}{60})[/tex]

= [tex]\displaystyle 5\frac{49}{60} }[/tex]

• d. 10 1/4 + 1 2/3 + 20 7/8

[tex]\displaystyle 10\frac{1}{4} + 1\frac{2}{3} + 20\frac{7}{8}[/tex]

= [tex]\displaystyle 10\frac{6}{24} + 1\frac{16}{24} + 20\frac{21}{24}[/tex]

= [tex](10 + 1 + 20) + (\displaystyle \frac{6 + 16 + 21}{24} )[/tex]

= [tex]31 + \displaystyle\frac{43}{24}[/tex]

= [tex]31 + \displaystyle 1\frac{19}{24}[/tex]

= [tex]\displaystyle 32\frac{19}{24}[/tex]

• e. 2,25 + 25% + 1 1/2

[tex]\displaystyle 2\frac{25}{100} + \frac{25}{100} + 1\frac{1}{2}[/tex]

= [tex]\displaystyle 2\frac{25}{100} + \frac{25}{100} + 1\frac{50}{100}[/tex]

= [tex](2 + 1) +(\displaystyle \frac{25+ 25 + 50}{100} )[/tex]

= [tex]\displaystyle 3 + \frac{100}{100}[/tex]

= 3 + 1

= 4