4/19-13/18

Let's calculate: $\frac{4}{19}-\frac{13}{18}$

ⓘ To add fractions, put them over the same denominator, then add the numerators. We choose $342$, the least common multiple of $19$ and $18$. Multiplying the numerator and the denominator by the same number does not change the fraction: $\frac{4}{19}-\frac{13}{18}$ = $\frac{4\times 18}{19\times 18}-\frac{13\times 19}{18\times 19}$ = $\frac{4\times 18-13\times 19}{19\times 18}$

$\frac{4\times 18-13\times 19}{19\times 18}$

ⓘ Perform multiplications before additions and subtractions: $4\times 18$ = $4\times (10+8)$ = $4\times 10+4\times 8$ = $40+32$ = $72$, $13\times 19$ = $(10+3)\times 19$ = $10\times 19+3\times 19$ = $190+57$ = $247$

ⅰ $19\times 18$ = $19\times (10+8)$ = $19\times 10+19\times 8$ = $190+152$ = $342$

$\frac{72-247}{342}$

ⓘ Calculate the numerator and denominator before dividing: $72-247$ = $-175$

▶Result:   $-\frac{175}{342}$

The numeric value of: $-\frac{175}{342}$ is:

▷ $\approx -0.5117$