Answer:
t=5.18 minute
Step-by-step explanation:
Using Newton's law of cooling

T is temperature of a cup of coffee at any time t
, is the temperature of the surrounding and k is a constant of proportionality in this negative because temperature is decreasing.


To find constant knowing the time and the temperature the first step of the change of energy in cup of coffee

Now using the constant of decreasing can find the time to be a 145 temperature the cup of coffee


Answer:
Step-by-step explanation:
57.6
You do 27 divided by 90 27/90=0.3 and then move the decimal two places which would give you 30%
Answer:
2(x + y)² - 9( x + y ) -5 = 0
⇒2(x + y)² - 10 (x+y) +1(x+y) -5 = 0
⇒2(x+y)(x + y - 5 ) + 1(x + y -5 ) = 0
taking (x + y -5 ) common ,
⇒(x + y -5 )[2(x + y) + 1] =0
⇒(x + y -5)(2x + 2y +1) =0
hope , you got this
Add them all.34,6000 and 15000 and 2900 and 4050