Answer:
<em>Numbers: 6 and -2</em>
Step-by-step explanation:
<u>Equations</u>
This question can be solved by inspection. It's just a matter of factoring 12 into two factors that sum 4. Both numbers must be of different signs and they are 6 and -2. Their sum is indeed 6-2=4 and their product is 6*(-2)=-12.
However, we'll solve it by the use of equations. Let's call x and y to the numbers. They must comply:
![x+y=4\qquad\qquad [1]](https://tex.z-dn.net/?f=x%2By%3D4%5Cqquad%5Cqquad%20%5B1%5D)
![x.y=-12\qquad\qquad [2]](https://tex.z-dn.net/?f=x.y%3D-12%5Cqquad%5Cqquad%20%5B2%5D)
Solving [1] for y:

Substituting in [2]

Operating:

Rearranging:

Solving with the quadratic formula:

With a=1, b=-4, c=-12:



The solutions are:


This confirms the preliminary results.
Numbers: 6 and -2
Answer:
$660
Step-by-step explanation:
You multiply 60 by 4 and get 240
Subtract 240 from 900
Answer:
82
Step-by-step explanation:
For this problem you would first round everything. 9.03 becomes 9, 19.87 becomes 20, 3.11 becomes 3 and 4.97 becomes 5. You then just do the problem. 9 + 20 = 29, multiplied by 3 makes 87, 87 - 5 = 82.
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