The sum of two numbers is 4 and their product is -32
Find the numbers.
2 answers
-4 and + 8
x+y = 4
xy = -32
so from the first: y = 4-x
into the second
x(4-x) = -32
4x - x^2 + 32 = 0
x^2 - 4x - 32 = 0
(x-8)(x+4) - 0
x = 8 or x = -4
if x=8 then y = -4
if x = -4 then y = 8
the numbers are 8 and -4
xy = -32
so from the first: y = 4-x
into the second
x(4-x) = -32
4x - x^2 + 32 = 0
x^2 - 4x - 32 = 0
(x-8)(x+4) - 0
x = 8 or x = -4
if x=8 then y = -4
if x = -4 then y = 8
the numbers are 8 and -4
1 answer