Question

What two numbers' sum=-4 and product=-2

Answer 1

Let a and b be the two numbers. Then

a + b = -4

a b = -2

Solve the second equation for b :

b = -2/a

Substitute this into the first equation:

a - 2/a = -4

Multiply both sides by a :

a² - 2 = -4a

Move 4a to the left side:

a² + 4a - 2 = 0

Use the quadratic formula to solve for a :

a = (-4 ± √(4² - 4(-2))) / 2

a = -2 ± √6

If a = -2 + √6, then

-2 + √6 + b = -4

b = -2 - √6

In the other case, we end up with the same numbers, but a and b are swapped.