Answer:
Step-by-step explanation:
x²/a² - y²/b² = 1
center (0,0)
vertex (3,0), so a = 3
focus (9,0)
e = 9/a = 3
directrices: x = ±a/e = ±1
Answer: -9 + 21 = t t = 12°C.
Step-by-step explanation: For this problem lets have t be equal to the original temperature in the beginning of the day. The equation -9 + 21 = t represents this situation because it states that if we add the degrees that dropped to the current degrees it will give us our original degrees.
Solve.
-9 + 21 = t (Simply add -9 + 21) -9 + 21 = (+12)
12 = t
So, the original degrees in the beginning of the day was 12°C.
Answer:
C. x + y = 743
x – y = 75
Step-by-step explanation:
Got it right.
Answer:
29 is your answer. I hope this helps you! Let me know if I got something wrong or if you need more help :)
Step-by-step explanation:
First, apply distributive property to 3(2+8). 3×2 and 3×8.

Add 6 and 24.

Simplify
.
is the same as 4×4. 4 times 4 is 16.

Add 15 and 30.

Subtract.

29 is your answer. I hope this helps you! Let me know if I got something wrong or if you need more help :)