What two numbers can you multiply to get 12 and add up to -7?

Answer 1

You have two equations:

x * y = 12

x + y = -7

Subtracting x from both sides, you can rearrange the second equation to

y = -7 -x

Substituting that into the first equation,

x * (-7 - x) = 12, or

-x⁲ - 7x = 12, or

x⁲ + 7x + 12 = 0

You can now factor that equation

x⁲ + 7x + 12 = (x + 3) * (x + 4) = 0

which means that either x+3=0 or x+4=0,

so your answer is -3 and -4

Double-checking:

• -3 + -4 = -7
• (-3) * (-4) = +12