Answer:
The substance half-life is of 4.98 days.
Step-by-step explanation:
Equation for an amount of a decaying substance:
The equation for the amount of a substance that decay exponentially has the following format:
In which k is the decay rate, as a decimal.
k-value of 0.1392.
This means that:
Find the substance's half life, in days.
This is t for which 
. So
The substance half-life is of 4.98 days.
Answer:
A 1:6
Step-by-step explanation:
3:18 simply to 1:6
Answer:
-37/6
Step-by-step explanation:
Answer:
x = 28 cm
Step-by-step explanation:
Given:
Area of link shaded regions = 84 cm²
Required:
The value of x (diameter of the semicircle/length of the rectangle)
Solution:
Diameter of the semicircle = 2r = x
Length of rectangle (L) = 2r = x
Radius of semicircle (r) = ½x
Width of rectangle (W) = radius of semicircle = ½x
Use 3.14 as π
Area of the link shaded regions = area of rectangle - area of semicircle
Thus:
Area of the link shaded regions = (L*W) - (½*πr²)
Plug in the values
84 = (x*½x) - (½*3.14*(½x)²)
84 = x²/2 - (1.57*x²/4)
84 = x²(½ - 1.57/4)
84 = x²(0.5 - 0.3925)
84 = x²(0.1075)
Divide both sides by 0.1075
84/0.1075 = x²
781.4 = x²
√781.4 = x
27.9535329 = x
x = 28 cm
