[latex]\frac{ 4}{10}+\frac{55}{100}=\\ \\their \ lcd \ is \ 100\\ \\ =\frac{ 40}{100}+\frac{55}{100} =\frac{95}{100}=\frac{19}{20}[/latex]

Just need the LCD That's 100 so [latex] \frac{4}{10} [/latex]⇒[latex] \frac{40}{100} [/latex] and [latex] \frac{40}{100} [/latex] + [latex] \frac{55}{100} [/latex] = [latex] \frac{95}{100}[/latex] OR just 19/20