Answer:
1914
Step-by-step explanation:
<u>Substitute "a" for 9</u> in the equation. Solve using the BEDMAS order (brackets, exponents, division, multiplication, addition, subtraction).
24a² - 30
= 24(9)²-30    The exponent only belongs to the 9. Square 9.
= 24(81) - 30    Multiply 24 and 81.
= 1944 - 30      Subtract 30 from 1944.  
= 1914              Answer
24a²-30 at 9 is 1914.