<em>5x + 2y = 25;</em>
<em>5x + 2y = 25;5x - y = 10;</em>
5x + 2y = 25;
5x = 10 + y;
(10 + y) + 2y = 25;
5x = 10 + y;
10 + 3y = 25;
5x = 10 + y;
3y = 15;
5x = 10 + y;
y = 5;
5x = 10 + y;
y = 5;
5x = 10 + 5;
y = 5;
5x = 15;
y = 5;
x = 3.
Answer: (3; 5).
-- point (1, -2)
-- point (10, 25)
To solve this we are going to use the half life equation

Where:

is the initial sample

is the time in years

is the half life of the substance

is the remainder quantity after

years
From the problem we know that:



Lets replace those values in our equation to find

:




We can conclude that after 1600 years of radioactive decay, the mass of the 100-gram sample will be
91.7 grams.
So 1 hour= 60 minutes
60+25= 85 minutes
Now we should subtract the 42
85-42=43
Answer:
$13.20
Step-by-step explanation:
total cost of tickets = $92.40
total number of tickets = 7
cost of each ticket
= total cost of tickets ÷ total number of tickets
= 92.40 ÷ 7
= $13.20
hope this helps