Answer:
C.) 87
Step-by-step explanation:
if you look at it from the other side, its counting down from 91 from the left.
Answer:
x = 12
Step-by-step explanation:
<u>To find "x"</u>, we need to <u>isolate it</u>. This means move "x" to the left side, and everything else to the right side.
When moving a number, do its <u>reverse operation</u> to the entire equation.
x + 9 = 2x - 3
x - 2x + 9 = 2x - 2x - 3 Subtract 2x from both sides
-x + 9 = -3
-x + 9 - 9 = -3 - 9 Subtract 9 from both sides
-x = -12
-x/-1 = -12/-1 Divide both sides by -1 to get rid of the negatives
x = 12 Final answer
Check your answer. Split the equation for the left and right sides. Substitute "x" for the answer "12".
LS: (left side)
x + 9
= 12 + 9 Add
= 21
RS: (right side)
2x - 3
= 2(12) - 3 Multiply before subtracting
= 24 - 3 Subtract
= 21
Both sides equal to 21 when "x" is 12.
LS = RS left side equals right side
Therefore the answer is correct.
It is 1.55 times the value of the second number.
Answer:
<em>M(13)=14.3 gram</em>
Step-by-step explanation:
<u>Exponential Decay Function</u>
The exponential function is used to model natural decaying processes, where the change is proportional to the actual quantity.
An exponential decaying function is expressed as:
![C(t)=C_o\cdot(1-r)^t](https://tex.z-dn.net/?f=C%28t%29%3DC_o%5Ccdot%281-r%29%5Et)
Where:
C(t) is the actual value of the function at time t
Co is the initial value of C at t=0
r is the decaying rate, expressed in decimal
The element has an initial mass of Mo=970 grams, the decaying rate is r=27.7% = 0.277 per minute.
The equation of the model is:
![M(t)=M_o\cdot(1-r)^t](https://tex.z-dn.net/?f=M%28t%29%3DM_o%5Ccdot%281-r%29%5Et)
![M(t)=970\cdot(1-0.277)^t](https://tex.z-dn.net/?f=M%28t%29%3D970%5Ccdot%281-0.277%29%5Et)
Operating:
![M(t)=970\cdot 0.723^t](https://tex.z-dn.net/?f=M%28t%29%3D970%5Ccdot%200.723%5Et)
After t=13 minutes the remaining mass is:
![M(13)=970\cdot 0.723^{13}](https://tex.z-dn.net/?f=M%2813%29%3D970%5Ccdot%200.723%5E%7B13%7D)
Calculating:
M(13)=14.3 gram