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:
sorry can we have more info?
Step-by-step explanation:
Answer:
A
Step-by-step explanation:
X + y = 150
x = y + 100
2y + 100 = 150
2y = 50
y = 25
shoes are 25 hoodie is 125
Answer:
y = - 
x + 10
Step-by-step explanation:
The equation of a line in slope- intercept form is
y = mc + c ( m is the slope and c the y- intercept )
Here m = - and crosses the y- axis at (0, 10 ) ⇒ c = 10
y = - x + 10 ← equation of line
