(4
15
7
−2
5
3
)∗15=(
15
4∗15+7
−
5
2∗5+3
)∗15=(
15
67
−
5
13
)∗15=
15
67
∗15−
5
13
∗15=
67−13∗3=67−39=28
2)
\displaystyle ( 1 \frac{11}{17} + 2 \frac{15}{34}) * 34=(\frac{28}{17} + \frac{83}{34}) *34= \frac{28}{17} * 34 + \frac{83}{34} * 34= 28*2+ 83= 56+83=139(1
17
11
+2
34
15
)∗34=(
17
28
+
34
83
)∗34=
17
28
∗34+
34
83
∗34=28∗2+83=56+83=139
3)
\displaystyle (5 \frac{1}{6} - 2 \frac{2}{3}) * 12= (\frac{31}{6} - \frac{8}{3}) * 12= \frac{31}{6} * 12 - \frac{8}{3} * 12 = 31*2 - 8*4= 62 - 32 = 30(5
6
1
−2
3
2
)∗12=(
6
31
−
3
8
)∗12=
6
31
∗12−
3
8
∗12=31∗2−8∗4=62−32=30
При а=7,3, 0.2а × 500= (0.2 × 7,3)×500= 1,46×500= 730