Answer: The answer is 8.
Step-by-step explanation: The first step is to convert the expression into figures. We shall call the unknown number Y. So if we are told “the square of a number,” that means Y squared, or better still, Y^2. Further we are told “the difference between the square of a number and 40” and that can be written as;
Y^2 - 40.
Next we are told that this expression is equal to 3 times that number (that is 3Y). That can now be written out as follows,
Y^2 - 40 = 3Y
If we move all expressions to one side of the equation, what we would have is,
Y^2 - 3Y -40 = 0
(Remember that when a positive value crosses to the other side of an equation it becomes negative and vice versa)
We now have a quadratic equation
Y^2 -3Y - 40 = 0
By factorizing we now have
(Y -8) (Y + 5) = 0
Therefore Y - 8 = 0 or
Y + 5 = 0
Hence, Y = 8 or Y = -5
Since we are asked to calculate the positive solution, Y = 8
Answer:
Step-by-step explanation:
<h3>to understand this</h3><h3>you need to know about:</h3>
- percent
- percentage words problem
- PEMDAS
<h3>given:</h3>
- population:2500
- decreasing rate:3%
<h3>to find:</h3>
- the population after 11 years
<h3>let's solve:</h3>
according to the question
population decreases in 1 year
population will decrease in 11 years
so the population of the town after 11 years will be
2500-825
<h2>1675</h2>
Answer: 1.25 hours
Step-by-step explanation: 600/120=5. Kin‘s travel time is 5 hours. 600/160=3.75. 5-3.75=1.25.
For every 2,3n there is 6n
