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
13x+6y = -30................y = -5 -13x/6
x−2y=−4...................... y = x/2 +2 <span>
If we graph both lines we can get the solution of the system (point of intersection)
The best estimate is (x,y) = (-2.625, 0.688)</span>
Ok.. if you got 84.99 as you answer then you would put .15 *99.99 then you would get 14.9985 then round and get 15.00 and then 99.99 - 15.00 ....you will get 84.99...i think
Answer:
$721.55
Step-by-step explanation:
658.95*1.095=721.55
