№4

4/15 - (у + 3/25) = 1/25

4/15 - у - 3/25 = 1/25

у = 4/15 - 3/25 - 1/25

у = 20/75 - 9/75 - 3/75

у = 8/75

№5

[tex](8 \frac{3}{14} - y) \div \frac{3}{7} = 17[/tex]

(115/14 - у) : 3/7 = 17

115/14 - у = 17 * 3/7

115/14 - у = 51/7

у = 115/14 - 51/7

у = 115/14 - 102/14

у = 13/14

№6

[tex]3 \frac{1}{16} \div (x - \frac{5}{16} ) = \frac{7}{8} [/tex]

49/16 : (х - 5/16) = 7/8

х - 5/16 = 49/16 : 7/8

х - 5/16 = (49/16)*(8/7)

х - 5/16 = 7/2

х = 7/2 + 5/16

х = 56/16 + 5/16

х = 61/16

[tex]x = 3 \frac{13}{16} [/tex]