All categories

3 years ago

What value of k will make this expression equal to 0? b • 3.8 • 2.72 • (k – 4)

Mathematics

2 answers:

Gelneren [198K]3 years ago

8 0

4
4-4=0
anything × 0 = 0

yuradex [85]3 years ago

7 0

Answer:The correct answer is 4

Step-by-step explanation:

4-4=0. Zero multiplied by anything will equal zero :3

You might be interested in

A roast turkey is taken from an oven when its temperature has reached 185 degrees F and is placed on a table in a room where the

Vedmedyk [2.9K]

(a) Using Newton's Law of Cooling, $\dfrac{dT}{dt} = k(T - T_s)$ , we have $\dfrac{dT}{dt} = k(T - 75)$ where T is temperature after T minutes.
Separate by dividing both sides by T - 75 to get $\dfrac{dT}{T - 75} = k dt$ . Integrate both sides to get $\ln|T - 75| = kt + C$ .

Since $T(0) = 185$ , we solve for C:
$|185 - 75| = k(0) + C\ \Rightarrow\ C = \ln 110$
So we get $\ln|T - 75| = kt + \ln 110$ . Use T(30) = 150 to solve for k:
$\ln| 150 - 75 | = 30k + \ln 110\ \Rightarrow\ \ln 75 - \ln 110= 30k \Rightarrow \\ k= \frac{1}{30}\ln (75/110) = \frac{1}{30}\ln(15/22)$

So

$\ln|T - 75| = kt + \ln 110 \Rightarrow |T - 75| = e^{kt + \ln110} \Rightarrow \\ \\
|T - 75| = 110e^{kt} \Rightarrow T - 75 = \pm110e^{(1/30)\ln(15/22)t} \Rightarrow \\
T = 75 \pm110e^{(1/30)\ln(15/22)t}$

But choose Positive because T > 75. Temp of turkey can't go under.

$T(t) = 75 + 110e^{(1/30)\ln(15/22)t} \\
T(45) = 75 + 110e^{(1/30)\ln(15/22)(45)} = 136.929 \approx 137{}^{\circ}F$

(b)

$T(t) = 75 + 110e^{(1/30)\ln(15/22)t} = 75 + 110(15/22)^{t/30} \\
100 = 75 + 110(15/22)^{t/30} \\
25 = 110(15/22)^{t/30} 
\frac{25}{110} = (15/22)^{t/30} \\
\ln(25/110) / ln(15/22) = t/30 \\
t = 30\ln(25/110) / ln(15/22) \approx 116\ \mathrm{min}$

Dogs of the AMS.

4 0

3 years ago

The isosceles triangle has a perimeter of 7.5 m.

RUDIKE [14]

Answer:

2.1 + 2x = 7.5

Step-by-step explanation:

3 0

3 years ago

Read 2 more answers

Which equation represents the line that is parallel to y = 4 and passes through (-3,1)?

Fiesta28 [93]

y=x thats all i khow

8 0

3 years ago

Read 2 more answers

Given f(X) =-X+ 6 write an equation for f(x + 3).

luda_lava [24]

Answer:

3 - x

Step-by-step explanation:

f(x) = -x + 6

f(x + 3)

Substitute (x + 3) in for x;

f(x + 3) = -(x + 3) + 6

= - x - 3 + 6

= -x + 3

3 0

2 years ago

If n lines are drawn in a plane, how many regions do they separate the plane into? induction

grandymaker [24]

Hello,

Let's assume i the number of lines,
u(i) the number of regions:

$u_0=1\\\\
u_1=2=1+1=1+u_0\\\\
u_2=4=2+u_1\\\\
u_3=7=3+u_2\\\\
u_4=11=4+u_3\\\\
u_5=16=5+u_4\\\\
...\\\\
\boxed{u_{n+1}=(n+1)+u_{n}}\\\\

u_{n+1}=(n+1)+n+(n-1)+...+1+u_0\\\\

\boxed{u_{n+1}= \dfrac{(n+1)*(n+2)}{2}+1 }$

6 0

3 years ago