To find the value of the expression b² - 12a when a = 1/4 and b = 8, substitute the given values into the expression:
b² - 12a = (8)² - 12(1/4)
Simplifying the expression further:
b² - 12a = 64 - 12(1/4)
Now, solve the multiplication and subtraction:
b² - 12a = 64 - 3
Finally, perform the subtraction:
b² - 12a = 61
Therefore, when a = 1/4 and b = 8, the value of the expression b² - 12a is 61.