Use Pythagorean theorem
a^2 + b^2 = c^2
Other words, lengths of the shortest sides squared are equal to the longest squared
a^2 + 9^2 = 15^2
a^2 + 81 = 225
a^2 = 144
a = squareroot of 144
a = 12
Solution: a = 12
Answer:

Step-by-step explanation:
Data provided in the question:
Initial volume of water = 15 liters
Concentration of salt = 4 liters per minute
x be the amount of salt, in grams, in the fish tank after t minutes have elapsed
The unknown concentration of incoming brine c.
Now,
Salt concentration per minute = 
For x amount of salt = 
Therefore,

Answer:
X = 15
Step-by-step explanation:
We move all terms to the left:
<em>x+8+2x-(2x+13)=0</em>
We add all the numbers together, and all the variables:
<em>3x-(2x+13)+8=0</em>
We get rid of parentheses:
<em>3x-2x-13+8=0</em>
We add all the numbers together, and all the variables:
<em>x-5=0</em>
We move all terms containing x to the left, all other terms to the right:
<em>x=5</em>
Answer:
x = 42-degrees
Step-by-step explanation:
x + 48 = 90 --> *subtract 48 from both sides*
x = 42