Answer
a) always true
b) always true
c) never true
Work Step by Step
a)
$5s + 7 \geq 7 + 5s$
$5s + 7 (-7) \geq 7 (-7)+ 5s$
$5s \geq 5s$
$5s (-5s) \geq 5s(-5s)$
$0 \geq 0$ (true statement)
b)
$4t + 6 \gt 4t -3$
$4t + 6 (+3) \gt 4t -3(+3)$
$4t + 9 \gt 4t$
$4t (-4t) + 9 \gt 4t (-4t)$
$9 \gt 0$ (true statement)
c)
$5(m+2) \lt 5m -4$
$5m + 10 \lt 5m -4$
$5m + 10 (-5m) \lt 5m -4 (-5m)$
$10 \lt -4$ (false statement)