Answer :
In a linear equation:
-- the highest power of the variable that appears is the first power
-- the equation has one solution at most
In a quadratic equation:
-- the highest power of the variable that appears is the second power
-- the equation has two solutions
-- the highest power of the variable that appears is the first power
-- the equation has one solution at most
In a quadratic equation:
-- the highest power of the variable that appears is the second power
-- the equation has two solutions
Quadratics always have a squared value and linears don't. Quadratics have 2 answers and linears have 1.