Answer:
It will take 15.029 years for element X to reach mass of 260 grams
Step-by-step explanation:
The half life period of radioactive element X is 26 years
The initial mass of radioactive element X is 260 grams
Elapsed time = half life * log (beginning amount /ending amount)/log 2
Substituting the given values, we get
Elapsed time = 26 * log (390/260)/log 2
= 15.209 years
Answer:
-7 =x
Step-by-step explanation:
−30=5(x+1)
Divide each side by 5
−30/5=5/5 (x+1)
-6 = x+1
Subtract 1 from each side
-6-1 = x+1-1
-7 =x
Answer:
15 dollars
Step-by-step explanation:
12 inches = 1 ft
so 12 inch by 12 inches is 1 ft * 1 ft
1 ft* 1 ft
1 ft^2
This is smaller than 3 ft^2 so they will get charged for 3 ft^2
3 ft^2 = 3 ft^2 * $5 / ft^2 = 15 dollars
Answer:the perimeter of the regular pentagon is 5x + 20
Step-by-step explanation:
The perimeter of a plane figure is the distance around the plane figure. The pentagon is a plane figure. It has 5 sides. Since it is a regular Pentagon, it means that all the sides are equal.
From the information given, the length of each side of the regular Pentagon is x + 4
The perimeter of the regular Pentagon would be 5 times the length of each side. It becomes
5(x + 4) = 5x + 20