I’m sorry I’m confused it’s all spaced out can you put it in the comments and I’ll answer in there? Hope you have a nice day!
Slope= 1
Y= 12
Equation= y = x + 12
We want to know when we brought it back in to the room. at that time
the temperature difference is 80 - 42 = 38 so we have to solve
<span>
38=9<span>e<span>^−.3344t</span></span></span> for t
this time we get
<span><span>38 / 9</span>=<span>e^<span>−.3344t</span></span></span>
<span>t=<span><span>ln(<span>38 / 9</span>)</span><span> / −.3344</span></span></span>
<span>t=−4.3</span>
so 4.3 minutes before 2:10
Direct variation is y=kx where k is a constant
the fiest way to see if it is direct or not, is if x increases, then y increases as well,
then we see if y=kx is valid, basically if we have a constant of variation
the first one x increase and y increase
see if same constant
y=kx
-4.5=-3k
1.5=k
so
see next one
-1 and 3
-3=-1(k)
-3=-1(1.5)
-3=-1.5
false
not it
2nd is increase and y decrease, so not direct variation
3rd is x is same but y increase so nope
4th is x increase and y increase, now test the constant
-7.5=-3k
2.5=k
-1 and -2.5
-2.5=-1k
-2.5=-1(2.5)
-2.5=-2.5
true
answer is last option