Given:
[tex]\dfrac{?}{5}+\dfrac{18}{20}=\dfrac{30}{20}[/tex]
To find:
The missing value.
Solution:
Let x be the missing value.
We have,
[tex]\dfrac{x}{5}+\dfrac{18}{20}=\dfrac{30}{20}[/tex]
[tex]\dfrac{x}{5}+\dfrac{9}{10}=\dfrac{3}{2}[/tex]
Subtract [tex]\dfrac{9}{10}[/tex] from both sides.
[tex]\dfrac{x}{5}=\dfrac{3}{2}-\dfrac{9}{10}[/tex]
[tex]\dfrac{x}{5}=\dfrac{15-9}{10}[/tex]
[tex]\dfrac{x}{5}=\dfrac{6}{10}[/tex]
[tex]\dfrac{x}{5}=\dfrac{3}{5}[/tex]
Multiplying both sides by 5, we get
[tex]x=3[/tex]
So, the missing value is 3.
Therefore, the correct option is C.
