Question

1/5 + 4/15= 2/3 - 5/12= 5 1/7 - 7 13/21= 8/15 - 2 23/30= -2x=-14 48x=-16 -25x=-1 -3=-1/3x -2/5x=3/10

Answer 1

1)1/5 + 4/15= 3+4/15=7/15

2)2/3 - 5/12= 8-5/12=3/12=1/4

3)5 1/7 - 7 13/21= 5/7-13/3=-76/21=-3 13/21.

4)8/15 - 2 23/30= 8/15-23/15=-1


1)-2x=-14
х=7

2)48x=-16
х=-1/3

3)-25х=-1
х=1/25

4)-3=-1/3x
9=х
х=9

5)-2/5x=3/10
х =-3/4=-0,75

Желаю удачи и до встречи;)

Answer 2

1/5 + 4/15 = (3/3)(1/5) + (1/3)(4/15) = 3/15 + 4/45 = (9/45) + (4/45) = 13/45

2/3 - 5/12 = (8/12) - (5/12) = 3/12 = 1/4

5 1/7 - 7 13/21 = (57 + 1)/7 - (73 + 13)/21 = 36/7 - 64/21 = (363)/(73) - (641)/(73) = 108/21 - 64/21 = 44/21

8/15 - 2 23/30 = 8/15 - (230 + 23)/30 = 8/15 - 83/30 = (82)/(152) - (832)/(30*2) = 16/30 - 166/30 = -150/30 = -5

-2x = -14 => x = 7

48x = -16 => x = -16/48 = -1/3

-25x = -1 => x = 1/25

-3 = (-1/3)x => x = 9

-2/5x = 3/10 => x = -(3/10) * -(5/2) = 3/4