[tex]\sf\dfrac{3}{10}+\dfrac{68}{100}[/tex]
Convert 3/10 to a fraction over 100. We do this by multiply 10 to the numerator and denominator.
[tex]\sf\dfrac{3}{10}\rightarrow\dfrac{3\times10}{10\times10}\rightarrow\dfrac{30}{100}[/tex]
Now we can add the numerators of the two fractions together and keep the denominator.
[tex]\sf\dfrac{30}{100}+\dfrac{68}{100}\rightarrow\dfrac{30+68}{100}[/tex]
[tex]\sf\dfrac{98}{100}[/tex]
Simplify by dividing 2 to the numerator and denominator:
[tex]\sf\dfrac{98\div2}{100\div2}\rightarrow\boxed{\sf\dfrac{49}{50}}[/tex]