Answer:
• for the first inequality:
[tex] \dashrightarrow \: { \tt{3(a - 5x) < 1 + x}} \\ \\ { \tt{3a - 15x < 1 + x}} \\ \\ { \tt{3a < 1 + 16x}} \\ \\ { \boxed{ \tt{a = \frac{1 + 16x}{3} \: \: { \red{}} }}}[/tex]
• for the second inequality:
[tex] \dashrightarrow \: { \tt{ \frac{2 - x}{2} > 3 + 5(x - a) }} \\ [/tex]
substitute for a:
[tex]{ \tt{ \frac{2 - x}{2} > 3 + 5(x - \frac{1 + 16x}{3} ) }} \\ \\ { \tt{ \frac{2 - x}{2} > 3 - \frac{5 + 80x}{3} }} \\ \\ { \tt{2 - x > 6 - \frac{10 + 160x}{3} }} \\ \\ { \tt{6 - 3x > 18 - 10 - 160x}} \\ \\ { \tt{157x > 2}} \\ \\ { \tt{x > \frac{2}{157} }}[/tex]
• substitute to get value of a: [ first inequality ]
[tex]{ \tt{a < \frac{1 + 16( \frac{2}{157}) }{3} }} \\ \\{ \boxed{ \tt{a < \frac{63}{157} }}}[/tex]
[ second inequality ]
[tex]{ \boxed{ \tt{a > \frac{65}{157} }}}[/tex]