1)(16 3/5+17 7/ 5/8-18 3/4) 2)4 2/5-(8 7/60+3 3/4-8 - вопрос №67195991163517758183424258760334871532579834 от 2Alinochka2 19.07.2021 00:50

Question

Математика: 1)(16 3/5+17 7/ 5/8-18 3/4) 2)4 2/5-(8 7/60+3 3/4-8 7/15) 3)25 7/9-8 3/4-(13 5 /12+2 11/18) 4)(20-19 3/4)+(17 3/4-17)+(2 1/2-17/24) распишите по действиям,

2Alinochka2 · Answer

1)(16 3/5+17 7/10)-(25 5/8-18 3/4)=27 17/40
16 3/5+17 7/10=16 6/10+17 7/10=33 13/10=34 3/10
25 5/8-18 3/4=25 5/8-18 6/8=7 5/8-6/8=7-1/8=6 7/8
34 3/10-6 7/8=34 12/40-6 35/40=28 12/40-35/40=28-23/40=27 17/40

2)4 2/5-(8 7/60+3 3/4-8 7/15)=1
8 7/60+3 3/4-8 7/15=8 7/60+3 45/60-8 28/60=3 24/60=3 2/5
4 2/5-3 2/5=1

3)25 7/9-8 3/4-(13 5 /12+2 11/18)=1
13 5 /12+2 11/18=13 15 /36+2 22/36=15 37/36=16 1/36
25 7/9-8 3/4-16 1/36=25 28/36-8 27/36-16 1/36=1

4)(20-19 3/4)+(17 3/4-17)+(2 1/2-17/24)=здесь проще открыть скобки и решить прямо
=20-19 3/4+17 3/4-17+(2 1/2-17/24)=(20-17)+(-19 3/4+17 3/4)+(2 1/2-17/24)=
=3-2+(2 12/24-17/24)=1+(2 -5/24)=1+1 19/24=2 19/24