What multiplies to -1920 and adds to 56?

Answer 1

-1864

Answer 2

To solve this you need to set up the following two equations:

xy=-1920 (since the two numbers multiply to -1920)

x+y=56 (since they add to 56)

In the first equation, solve for x. We have x=-1920/y

Substitute this value for y in the other equation.

(-1920/y)+y=56

Multiply both sides by y

-1920 + y^2 = 56y

Subtract 56y from both sides.

y^2 - 56y - 1920 = 0

Solve this by completing the square or using the quadratic formula to get that y is equal to 80 or -24. You will see that 80-24=56 and (80)(-24)= -1920

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