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:
4/9 or four out of nine
Step-by-step explanation:
There are nine pencils total, and 4 of them are orange
Turn 14 into 16, 4 x 4 = 16, 4 x 8 = 32, 32 x 4 = 128cm
56:7=24:3
3x3=27:3
8x2=64:4
45:9=35:7
4x5=10x2
42:6=63:9
28:4=7x1
2x2=36:9
It CAN'T equal 21, since 9+10=19
BUT, if the 9 was changed to like, 11 - Then it would = 21, or if the 10 was changed to a 12, it would make 21 also,
