Answer:
(1, 2), (2, -3), (3, 4), (4, -5)
Step-by-step explanation:
Do 12x-9 + 141 = 180 (add -9 and 4)
12x +132= 180 (Subtract 132 from 180)
12x =48 (Divide 48 by 12)
x=4
Answer: 4573.8
Equation:
1/3*pi*r^2*h
The cookies because if they have 100°C, after 30 seconds it loses half it‘s heat and now it only has 50°C.
After the next 30 seconds it loses again half the heat so it‘s 25°C.
You can theoretically continue this forever. It‘s exponential decay.
Answer:
x= 32.3 (3 s.f.)
θ= 21.8° (1 d.p.)
α= 68.2° (1 d.p.)
Step-by-step explanation:
Applying Pythagoras' Theorem,
x²= 12² +30²
x²= 144 +900
x²= 1044
Square root both sides:

x= 32.3 (3s.f.)



θ= 21.801° (3 d.p.)
θ= 21.8° (1 d.p.)


= 68.2° (1 d.p.)
Alternatively,
α +θ +90°= 180° (∠ sum of triangle)
α +21.801° +90°= 180°
α +111.801°= 180°
α= 180° -111.801°
α= 68.199°
α= 68.2° (1 d.p.)