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jessla314
The factors of 42 are 1,42,2,21,3,14,6,7. Non of these add together to get 9. One would have to be positive and the other negative but it still doesn't work.
JvitorBR
Hi,

x+y = 9 ⇒ x = 9-y
x·y = -42 

(9-y)·y = -42
9y-y² = -42
y²-9y-42 = 0 for a = 1, b = -9 e c = -42

Δ = b²-4ac
Δ = (-9)²-4(1)(-42)
Δ = 81+168
Δ = 249

y₁ = (-b+√Δ)/2a = (-(-9)+√249)/2(1) = (9+√249)/2 = 9/2 + √249/2
y₂ = (-b-√Δ)/2a = (-(-9)-√249)/2(1) = (9-√249)/2 = 9/2 - √249/2

For y = 9/2 + √249/2 

x+y = 9
x = 9-y
x = 9-(9/2 + √249/2)
x = 9/2 - √249/2

For y = 9/2 - √249/2

x+y = 9
x = 9-y
x = 9-(9/2 - √249/2)
x = 9/2 + √249/2

Answer:

Numbers: 9/2 + √249/2 and 9/2 - √249/2

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