Answer:
Option number B
Step-by-step explanation:
As per the statement:
Pieter wrote and solved an equation that models the number of hours it takes to dig a well to a level of 72 feet below sea level.
Given the equation as:
7h - 5 ( 3h -8 ) = -72
Using distributive property,
a ⋅ ( b + c ) = a ⋅ b + a ⋅ c
7h - 15h + 40 = - 72
Combine like terms;
-8h + 40 = -72
Subtract 40 from both sides we have;
-8h 8= -112
Divide both sides by -8 we have;
h = 14 hours
Therefore, the statement is true about Pieter’s solution is, It must be a positive number since it represents a number of hours.
X(x+2) = 48
x^2 + 2x = 48
x^2 + 2x - 48 = 0
*Use quadratic formulae*
x = 6
Numbers are 6 and 8
C is 23 because if you get all rhe numbers and measure thats your answer. I think i might be wrong. if I am then sorry
Answer:
The expression that represents the number of days until only 10% remains is T((d) 10 %) =100×
.
Step-by-step explanation:
The equation for half life is of the form
A = A₀×
.........................................................................(1)
Where
A = Final amount
A₀ = Initial amount
t = Time
h = Half life
For the equation T(d) = 100×2⁽⁻²⁾....................................(2)
We have by comparison with the equation for half life
2 ≡ 
and and the equation (2) can be written as
Percentage remaining after 2 half lives is
×100=100×
However if the half life of Technetium-99m is 6 hours then we have for one day
×100=100×
Therefore an expression that represents the number of days until only 10% remains is
×100=100×
= 10 %
=
= ㏑ = ㏑()
= 
×㏑
= ㏑()
= 
= 3.322
Therefore the expression for the number of days 10 % of Technetium-99m will be remaining is
T((d) 10 %) =100×
