Упростите выражения:

1. (x+2,3)-(x + 7,8) = x + 2,3 - x - 7,8 = 2,3 - 7,8 = <strong>-5,5</strong>
2. -(7,2-y) + (- y + 1,6) = -7,2 + y - y + 1,6 = -7,2 + 1,6 = <strong>-5,6</strong>
3. -(y-7,4+x) - (11,6-y) = -y + 7,4 - x - 11,6 + y = 7,4 - x - 11,6 = <strong>-x - 4,2</strong>
4. (y +13)-(13,5x - y + 4) = y + 13 - 13,5x + y - 4 = 2y + 9 - 13,5x = <strong>-13,5x + 2y + 9</strong>
5. (-2,6 + x + y)-(x-y-2,6) = -2,6 + x + y - x + y + 2,6 = x - x + y + y - 2,6 + 2,6 = <strong>2y</strong>
6. 8a+19a- 28a + 3a = 8a + 19a + 3a - 28a = 30a - 28a = <strong>2a</strong>
7. - 4x + 11x + 35x-38x = -4x + 11x + 35x - 38x = 11x + 35x - 4x - 38x = 46x - 42x = <strong>4x</strong>
8. 1,4а-а + в - 2,6в = 1,4a - a + b - 2,6b = 1,4a - a + b - 2,6b = 0,4a - 1,6b = <strong>0,4a - 1,6b</strong>
9. 1,6y-1,2-3,1y + 0,8 = 1,6y - 3,1y - 1,2 + 0,8 = -1,5y - 0,4 = <strong>-1,5y - 0,4</strong>
10. 1,1р + 0,9к – 1,2 - 1,3р - 3,8к = 1,1p - 1,3p + 0,9k - 3,8k - 1,2 = -0,2p - 2,9k - 1,2 = <strong>-0,2p - 2,9k - 1,2</strong>
11. 7(4a + 6) - 1,2a = 28a + 42 - 1,2a = 28a - 1,2a + 42 = 26,8a + 42 = <strong>26,8a + 42</strong>
12. 8x-4(16-2x) = 8x - 64 + 8x = 8x + 8x - 64 = 16x - 64 = <strong>16x - 64</strong>
13. 1,7(a-4) + 0,6(6-2a) = 1,7a - 6,8 + 3,6 - 1,2a = 1,7a - 1,2a - 6,8 + 3,6 = 0,5a - 3,2 = <strong>0,5a - 3,2</strong>
14. 1,5(8x-6y) - 2,4(5y - 3x) = 12x - 9y - 12y + 7,2x = 12x + 7,2x - 9y - 12y = 19,2x - 21y = <strong>19,2x - 21y</strong>
15. -(4,3x-2,4) - (5,8-2,6x) = -4,3x + 2,4 - 5,8 + 2,6x = -4,3x + 2,6x + 2,4 - 5,8 = -1,7x - 3,4 = <strong>-1,7x - 3,4</strong>
16. 0,6(4x-12) - 0,4(5x - 7) = 2,4x - 7,2 - 2x + 2,8 = 2,4x - 2x - 7,2 + 2,8 = 0,4x - 4,4 = <strong>0,4x - 4,4</strong>
17. 5$$\frac{1}{7}$$(y-7)-3$$\frac{3}{7}$$(14-y) = $$\frac{36}{7}$$(y-7)-$$\frac{24}{7}$$(14-y) = $$\frac{36}{7}$$y - $$\frac{36 \cdot 7}{7}$$ - $$\frac{24 \cdot 14}{7}$$ + $$\frac{24}{7}$$y = $$\frac{36}{7}$$y + $$\frac{24}{7}$$y - 36 - 48 = $$\frac{60}{7}$$y - 84 = <strong>$$\frac{60}{7}$$y - 84</strong>
18. $$\frac{5}{6}$$a+$$\frac{7}{8}$$в+$$\frac{7}{12}$$a-$$\frac{5}{12}$$в = $$\frac{5}{6}$$a + $$\frac{7}{12}$$a + $$\frac{7}{8}$$b - $$\frac{5}{12}$$b = $$\frac{10}{12}$$a + $$\frac{7}{12}$$a + $$\frac{21}{24}$$b - $$\frac{10}{24}$$b = $$\frac{17}{12}$$a + $$\frac{11}{24}$$b = <strong>$$\frac{17}{12}$$a + $$\frac{11}{24}$$b</strong>
19. $$\frac{8}{15}$$(3$$\frac{3}{4}$$x - $$\frac{5}{16}$$y)-$$\frac{3}{20}$$(6$$\frac{2}{3}$$x-4$$\frac{4}{9}$$y) = $$\frac{8}{15}$$($$\frac{15}{4}$$x - $$\frac{5}{16}$$y)-$$\frac{3}{20}$$($$\frac{20}{3}$$x - $$\frac{40}{9}$$y) = $$\frac{8}{15}$$ $$\cdot$$ $$\frac{15}{4}$$x - $$\frac{8}{15}$$ $$\cdot$$ $$\frac{5}{16}$$y - $$\frac{3}{20}$$ $$\cdot$$ $$\frac{20}{3}$$x + $$\frac{3}{20}$$ $$\cdot$$ $$\frac{40}{9}$$y = 2x - $$\frac{1}{6}$$y - x + $$\frac{2}{3}$$y = 2x - x - $$\frac{1}{6}$$y + $$\frac{4}{6}$$y = x + $$\frac{3}{6}$$y = <strong>x + $$\frac{1}{2}$$y</strong>
20. -(9,4 - в) +(- в + 3,7) = -9,4 + b - b + 3,7 = -9,4 + 3,7 + b - b = <strong>-5,7</strong>