212°F
147°F
23.2 min
1) Initial temperature for t=0
T(0)=68+144e^(0)=68+144=212°F
2) After 15 min
T(15)=68+144e^(-0.04*15)=68+144e^(-0.6)=147°F
3) 125°F -> t=?
125=68+144e^(-0.04t)
144e^(-0.04t)=125-68=57
e^(-0.04t)=57/144=0.4 you can apply ln on both sides:
-0.04t=ln(0.4) solving you get t=23.3 min
Answer:
x= -2/5
Step-by-step explanation:
(5x+2)=0
-2 -2
5x=-2
------------
5
x= -2/5
Answer:
$412.50
Step-by-step explanation:
15% of 2750 = 0.15 × 2750 = 412.5