if p(x) = px^7 + qx^3 + rx - 5

where p , q , r are constants ,
if p(-7) = 7 then p(7) = ?

p(x) = (px^7+qx^3+rx) - 5

p(-x) = -(px^7+qx^3+rx) - 5

p(-x) + 5 = -(p(x)+5)
p(-7) + 5 = -p(7) - 5
p(-7) = 7 - 10
p(-7) = -3