\(\frac{21.19+19.79}{38.50}\)
\(=\frac{19.\left(21+79\right)}{38.50}\)
\(=\frac{19.100}{38.50}\)
\(=\frac{19.2.50}{19.2.50}\)
\(=1\)
21 × 19 + 19 × 79 / 38 × 50
= 21 × 19 + 0,79
= ( 20 + 1 ) × 19 + 0,79
= 20 × 19 + 1 × 19 + 0,79
= 380 + 19 + 0,79
= 399 + 0,79
= 399,79
\(\frac{21\cdot19+19\cdot79}{38\cdot50}\)
\(=\frac{19\left(21+79\right)}{38\cdot50}\)
\(=\frac{19\cdot100}{38\cdot50}\)
\(=\frac{19\cdot50\cdot2}{19\cdot2\cdot50}=1\)