Oblicz.Pamiętaj o kolejności wykonywania działań
0,75 : 1/3 + 1,28 :0,04 - 2 1/4 x (3,5 - 2 1/3) + 1,65
Wychodzi mi 33 1/40 czyli 33,025 , a w książce wynik jest 33,275

Respuesta :

frika

Answer:

33.275

Step-by-step explanation:

1 step: Difference in brackets

[tex]3.5-2\dfrac{1}{3}=3\dfrac{1}{2}-2\dfrac{1}{3}=(3-2)+\left(\dfrac{1}{2}-\dfrac{1}{3}\right)=1+\dfrac{3-2}{3\cdot 2}=1+\dfrac{1}{6}=1\dfrac{1}{6}[/tex]

2 step: [tex]0.75\div\dfrac{1}{3}[/tex]

[tex]0.75\div\dfrac{1}{3}=\dfrac{75}{100}\div \dfrac{1}{3}=\dfrac{3}{4}\times \dfrac{3}{1}=\dfrac{9}{4}[/tex]

3 step: [tex]1.28\div 0.04[/tex]

[tex]1.28\div 0.04=128\div 4=32 \ \text{Move point two decimal places}[/tex]

4 step:

[tex]2\dfrac{1}{4}\times 1\dfrac{1}{6}=\dfrac{2\cdot 4+1}{4}\times \dfrac{1\cdot 6+1}{6}=\dfrac{9}{4}\times \dfrac{7}{6}=\dfrac{63}{24}=\dfrac{21}{8}[/tex]

5 step:

[tex]\dfrac{9}{4}+32-\dfrac{21}{8}+1.65=(32+1.65)+\left(\dfrac{9}{4}-\dfrac{21}{8}\right)=33.65+\dfrac{9\cdot 2-21}{8}=33.65-\dfrac{3}{8}=33.65-0.375=33.275[/tex]