Математика 6 класс учебник Мерзляк, Полонский ответы – номер 1481

1) 2,5х = –1;
х = –0,4;

2) 0,3х = 1;
х = 10/3;
х = 31/3;

3) 7х = –3;
х = –3/7;

4) –16х = 8;
х = –0,5;

5) |х| + 3,2 = 8;
|х| = 4,8;
х = 4,8 и х = –4,8;

6) 4,1 – |х| = 5;
|х| = –0,9;
Нет решений.;

7) |3х + 1,8| = 0;
3х + 1,8 = 0;
3х = –1,8;
х = –0,6;

8) 7/4 = х/2;
4х = 14;
х = 3,5;

9) (х + 3)/12 = 4/3;
3(х + 3) = 48;
3х + 9 = 48;
3х = 39;
х = 13;

10) 0,4х – 6 = 0,6х – 9;
0,6х – 0,4х = 9 – 6;
0,2х = 3;
х = 15;

11) 3х + 16 = 9 – 10х;
3х + 10х = 9 – 16;
13х = –7;
х = –7/13;

12) 0,6(х + 1 2/3) = –1,2;
х + 12/3 = –2;
х = –32/3;

13) –3,4(х + 93/11) = –68;
х + 93/11 = 20;
х = 1911/11 – 93/11;
х = 108/11;

14) 3(1 – х) + 5(х + 2) = 1 – 4х;
3 – 3х + 5х + 10 = 1 – 4х;
2х + 13 = 1 – 4х;
2х + 4х = 1 – 13;
6х = –12;
х = –2;

15) 3(2 – х) – (5х + 4) = 0,4 – 16х;
6 – 3х – 5х – 4 = 0,4 – 16х;
–8х + 2 = 0,4 – 16х;
16х – 8х = 0,4 – 2;
8х = –1,6;
х = –0,2;

16) 2(3 – 5p) = 4(1 – p) – 1;
6 – 10p = 4 – 4p – 1;
10p – 4p = 6 – 4 + 1;
6p = 3;
p = 0,5.