It’s 7 because it is on the exterior, and the other side, of the the parallel lines from 2.
To model half-life, use the formula

. Here,

is the amount remaining after a length of time

.

is the amount that you start with.

is the half-life. You plug in 50 for

, 10 for

, and 25 for

. You get

.
Multiply the weight in tonnes by the conversion factor ( 1 tonne = 1000 kg) to get the weight in kg's:
170 tonnes x 1000 = 170,000
Now convert to scientific notation, by moving the decimal point to have only 1 digit to the left of the decimal.
To do this, you would need to move the decimal 5 places to the left to get 1.70000
Now remove the 0's and multiply the number by 10 raised to the number of paces the decimal was moved to get:
1.7 x 10^5 kg's.
Answer:
27
Step-by-step explanation:
Let <em>g </em>be Gabrielle's age and <em>m </em>be Mikhail's age.
We can turn the statements the problem gives us into mathematical expressions to help us solve.
Gabrielle's age is two times Mikhail's age:
<em>g </em>= 2<em>m</em>
The sum of their ages is 81:
<em>g </em>+ <em>m </em>= 81
This gives us a system of equations that will allow us to solve for Gabrielle's age.
<em>g </em>+ <em>m </em>= 81
(2<em>m</em>)<em> </em>+ <em>m </em>= 81
3<em>m </em>= 81
<em>m</em> = 
<em>m </em>= 27
If we need to solve for Gabrielle's age, we can do the following.
<em>g </em>= 2<em>m</em>
2(27)<em> </em>= <em>g</em>
54 = <em>g</em>
g = 54
Mikhail's age is 27.
Gabrielle's age is 54.