7/13-19/20

Let's evaluate: $\frac{7}{13}-\frac{19}{20}$

ⓘ To add fractions, put them over the same denominator, then add the numerators. We choose $260$, the least common multiple of $13$ and $20$. Multiplying the numerator and the denominator by the same number does not change the fraction: $\frac{7}{13}-\frac{19}{20}$ = $\frac{7\times 20}{13\times 20}-\frac{19\times 13}{20\times 13}$ = $\frac{7\times 20-19\times 13}{13\times 20}$

$\frac{7\times 20-19\times 13}{13\times 20}$

ⓘ Perform multiplications before additions and subtractions: $7\times 20$ = $140$, $19\times 13$ = $19\times (10+3)$ = $19\times 10+19\times 3$ = $190+57$ = $247$

ⅰ $13\times 20$ = $(10+3)\times 20$ = $10\times 20+3\times 20$ = $200+60$ = $260$

$\frac{140-247}{260}$

ⓘ Calculate the numerator and denominator before dividing: $140-247$ = $-107$

▶Result:   $-\frac{107}{260}$

The numeric value of: $-\frac{107}{260}$ is:

▷ $\approx -0.4115$