решать только номер 508 и номер 511​

Это номер 508 (смотри фото)

В решении.

Пошаговое объяснение:

508. Сразу решение:

1) -х=10 и 3/7 - 19 и 1/3

х= 19 и 1/3 - 10 и 3/7

х=9 и (7*1 - 3*3)/21 =

=8 и (28-9)/21=

=8 и 19/21;

2) -х= -30,2 + 22,25

х=30,2 - 22,25

х=7,95;

3) -х= -20 и 5/9 - 27 и 1/3

х= 20 и 5/9 + 27 и 1/3

х= 47 и (5+3)/9

х=47 и 8/9;

4) -х= -17 и 1/7 + 5,5

х= 17 и 1/7 - 5 и 1/2

х=12 и (2*1 - 7*1)/14=

=11 и (16-7)/14=

=11 и 9/14.

511. 1)

а) 8 и 1/42 - 12 и 4/21=

= - (12 и 4/21 - 8 и 1/42)=

= - (4 и (2*4-1)/42=

= -4 и 7/42=

= -4 и 1/6;

б) 5 и 1/42 - 3 и 3/7=

=2 и (1-6*3)/42=

=1 и (43-18)/42=

=1 и 25/42;

в) -4 и 1/6 - 1 и 25/42=

= -(4 и 1/6 + 1 и 25/42)=

= -(5 и (7+25)/42)=

= - 5 и 32/42=

= -5 и 16/21. ответ.

2)

а)25 и 5/8 - 28 и 1/2=

= -( 28 и 1/2 - 25 и 5/8)=

= -(3 и (4*1-5)/8)=

= -(2 и (12-5)/8)=

= -2 и 7/8;

б) -19 и 7/16 - (-2 и 7/8)=

= -19 и 7/16 + 2 и 7/8=

= -(19 и 7/16 - 2 и 7/8=

= -(17 и (7-14)/16)=

= - (16 и (23-14)/16)=

= -16 и 9/16;

в) -16 и 9/16 - 3/4=

= - (16 и 9/16 + 3/4)=

= -(16 и (9+12)/16)=

= -16 и 21/16=

= -17 и 5/16.  ответ.