Question

Find two integers whose sum in -7 an whose product is 12

Answer 1

Given ,

Let numbers be a and b

Then,

1> a * b = 12

    b = 12 / a        ( equation i )

2> a + b = -7

    a + ( 12/a ) = -7

    a^2 + 12  = -7a

    a^2 + 7a + 12 = 0

    a^2 + 4a + 3a + 12 = 0

    a ( a + 4) + 3 (a + 4) = 0

    ( a + 4 ) ( a + 3 ) = 0

   

Finally , Either 1. a + 4 = 0   /  or, a = -4  And 2. b = 12 / a = -3

                       2. a + 3 = 0   /  or, a = -3  And 2. b = 12 / a = -4

Hence, the integers are -3 and -4