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.
X+4+3x =
4x+4 (you sum the like terms )
X=4
Step 1: Simplify both sides of the equation.
1.5(x+4)-3=4.5(x-2)
(1.5)(x)+(1.5)(4)+ -3 =(4.5)(x)+(4.5)(-2)
(1.5x) + ( 6+-3) =4.5x - 9
(Combine like terms)
1.5x+3=4.5x-9
Step 2: Subtract 4.5x from both sides.
1.5x +3 -4.5x =4.5x=-9-4.5x-3x+3=-9
Step 3: Subtract 3 from both sides.
-3x+3-3=-9-3
-3x=12
Step 4: Divide both by -3
-3x/-3=-12/-3
X=4
Answer:
Step-by-step explanation:
(B^2)(B^4) = B^(2+4)= B^6
answer is B
First step
12 x 1.3
Second step
15.6 x 7.5
The answer is 117 :)