I think the answer is $560
working:
$875 * 64% = $560
(-4)^2-4(1)(5)
16-4(1)(5)
16-4(5)
16-20
-4
The discriminant is negative so there are no real number solutions.
Round down to 10. 13 goes to 10.
Answer: option d. the argument is valid by the law of detachment.
The law of detachment consists in make a conlcusion in this way:
Premise 1) a => b
Premise 2) a is true
Conclusion: Then, b is true
Note: the order of the premises 1 and 2 does not modifiy the argument.
IN this case:
Premise 1) angle > 90 => obtuse
Premise 2) angle = 102 [i.e. it is true that angle > 90]]
Conclusion: it is true that angle is obtuse
