
William W. answered 03/18/20
Math and science made easy - learn from a retired engineer
Let the two numbers be "x" and "y". so:
x + y = 1 and
x•y = 12
Taking the first equation (x + y = 1) and solving it for x, we get y = 1 - x
Plugging "1 - x" into equation two wherever we see a "y", we get:
x•(1 - x) = 12
x - x2 = 12 [now, adding x2 and subtracting x from both sides of the equation we get:
0 = x2 - x + 12
This equation is not factorable so we would need to use the quadratic formula to solve it.
The quadratic formula is:
So a = 1, b = -1, and c = 12 meaning:
x = [-(-1) ± √((-1)2 -4(1)(12))]/(2(1)]
x = (1 ± √-47)/2 = 1/2 ± √47/2i
So, in other words there are no REAL numbers that add to 1 and multiply to 12. But there are two complex (imaginary) numbers that do. They are 1/2 + √47/2i and 1/2 - √47/2i
Karen J.
Thank you. I came to the same conclusion but wanted to make sure I was correct.03/18/20