As per the isosceles triangle theorem, if the two base angles are congruent then the legs are also congruent, so we must set the two legs equal to each other:
2z - 15 = 9
Add 15 to both sides:
15 - 15 = 0
15 + 9 = 24
Divide 2 from each side:
2z = 24
2z/2 = z
24/2 = 12
z = 12
Hence, the answer would be D: z = 12
SOLUTION:
Case: Percentages
Method:
The sale price after 30% off is $6800
Let the original price be 'x'
30% off means 70% of the original price

Final answer: (Nearest cents)
The original price was $9714.29
To find where the second derivative of the function changes sign, from negative to positive, or vice-versa. So, we find the second derivative of the given function.
Answer:
176. Multiply 6 by 2 thirds.
Step-by-step explanation: