Question

Find two integers whose sum is -20 and product is 99

Answer 1

Explanation:

let the integers be x and y

x+y=-20

y=-20-x

xy=99

x(-20-x)=99

-20x-x²=99

x²+20x+99=0

x²+11x+9x+99=0

x(x+11)+9(x+11)=0

(x+11)(x+9)=0

x=-11,-9

when x=-11

-11+y=-20

y=-20=11=-9

when x=-9

-9+y=-20

y=-20+9=-11

so integers are -11,-9