Question

1) Resolva as inequações a) 3x+7>19 b) 5x-10< 3x+4 c) 4.( x+2) +1 > 3 . (x+4 )

Answer 1

$a) 3x+7\ \textgreater \ 19\to 3x\ \textgreater \ 19-7\to 3x\ \textgreater \ 12\to x\ \textgreater \ \frac{12}{3} \to x\ \textgreater \ 4\\\\\\ S= \left \{xER| x\ \textgreater \ 4 \left \}$




$b) 5x-10\ \textless \ 3x+4\to 5x-3x\ \textless \ 4+10\to 2x\ \textless \ 14\to x\ \textless \ \frac{14}{7} \to x\ \textless \ 7 \\\\\\S= \left \{xER| x\ \textless \ 7 \left \}$




$c) 4.( x+2) +1 \ \textgreater \ 3 . (x+4 )\to 4x+8+1\ \textgreater \ 3x+12\to \\\\4x-3x\ \textgreater \ 12-8-1\to x\ \textgreater \ 3 \\\\\\ S= \left \{xER| x\ \textgreater \ 3 \left \}$