7. Упростим выражение и найдем его значение:
* 1) -1,3 - x + 5,1 при x = -2$$\frac{1}{4}$$ = -2.25
-1.3 - (-2.25) + 5.1 = -1.3 + 2.25 + 5.1 = 0.95 + 5.1 = 6.05
* 2) 1$$\frac{1}{6}$$ - y - 5$$\frac{7}{24}$$ при y = -3,4 = -3$$\frac{2}{10}$$ = -3$$\frac{1}{5}$$ = -3$$\frac{24}{120}$$
1$$\frac{1}{6}$$ - (-3$$\frac{1}{5}$$) - 5$$\frac{7}{24}$$ = 1$$\frac{1}{6}$$ + 3$$\frac{1}{5}$$ - 5$$\frac{7}{24}$$ = 1$$\frac{20}{120}$$ + 3$$\frac{24}{120}$$ - 5$$\frac{35}{120}$$ = 4$$\frac{44}{120}$$ - 5$$\frac{35}{120}$$ = -1 + $$\frac{44}{120}$$ - $$\frac{35}{120}$$ = -1 + $$\frac{9}{120}$$ = -1 + $$\frac{3}{40}$$ = -$$\frac{37}{40}$$ = -0.925
Ответ: 1) 6.05; 2) -0.925