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:
3/8 (Decimal: 0.375)
Step-by-step explanation:
Answer:
2.25 and 4.95
Step-by-step explanation:
x + y = 7.2
x - y = 2.7
x = 7.2 - y
x - y = 2.7
(7.2 - y) - y = 2.7
7.2 - 2y = 2.7
-2y = 2.7 - 7.2
-2y = -4.5
-2y/-2 = -4.5/-2
y = 2.25
x + y = 7.2
x + 2.25 = 7.2
x = 7.2 - 2.25
x = 4.95
Check: 4.95 and 2.25
x + y = 7.2
(4.95) + (2.25) = 7.2
7.2 = 7.2
x - y = 2.7
(4.95) - (2.25) = 2.7
2.7 = 2.7
y=2(3)x+1
−
y=2(3)x
y-y=2(3)x+1−2(3)x
the answer would be 0=1
but if it is asking u if it is false or true it is
0=1 is false, therefore the system of equations has no solutions
