Answer:
15%
Step-by-step explanation:
You'll save 5 cents by doing the 15%
Answer:
D.(1,1)
Step-by-step explanation:
Just plug in each pair of values in the multiple choice answers for x and y.
If we plug in (1,1)
The equation is
4(1) +5(1) ≤ 20
4+5≤ 20
9≤ 20
Since 9 is less than 20 we know statement is true, so we know (1,1) is a solution.
If we were to plug in any other choice like (0,5), the right side of the equation would be greater than 20 and the statement would not be true.
Answer:
8
Step-by-step explanation:
Newton's Law of Cooling
Tf=Ts+(Ti-Ts)e^(-kt) where Tf is temp at time t, Ts is temp of surroundings, Ti is temp of object/fluid. So we need to find k first.
200=68+(210-68)e^(-10k)
132=142e^(-10k)
132/142=e^(-10k)
ln(132/142)=-10k
k=-ln(132/142)/10
k≈0.0073 so
T(t)=68+142e^(-0.0073t) so how long until it reaches 180°?
180=68+142e^(-0.0073t)
112=142e^(-0.0073t)
112/142=e^(-0.0073t)
ln(112/142)=-0.0073t
t= -ln(112/142)/(0.0073)
t≈32.51 minutes
I think it would be b but
i’m not sure about the other one