Answer:1. x² + 9x + 20 = 015 - 6h² = 10m² = 6m - 72. quadratic equations has the degree of 2, and an equal sign (=). 3. boxed 2t² < 21 - 9tr² + 10r ≤ -162s² + 7s + 5 > 0(4x² - 25 = 0)'3w² + 12w 20these are not quadratic equations because they have inequality symbols such as <, >, and ≤. 4. they are quadratic inequalities. they differ from quadratic equations through symbols such as <, >, ≤, ≥, and ≠. Step-by-step explanation:may 3 lang akong concern :1. boxed 2t² < 21 - 9t2. 3w² + 12w 203. (4x² - 25 = 0)'naguguluhan ako, bakit ganto ayos na. kaya sa not quadratic ko sila isinama. yung no. 3 kung wala lang parenthesis, pasok sya sa quadratic e. at yung no. 2 naman, depende sa sign nya, kaso walang sign e. pero sana, nakatulong to.