Find two numbers whose product is 88 and the sum is - 19​

Sagot :

Answer: -8 and -11

Step-by-step explanation:

Let the first and second numbers be x and y.

Product of the two numbers is 88, therefore:
xy = 88

Sum of the two numbers is -19, therefore:
x + y = -19

Solve simultaneously by first finding y in terms of x in preferably the second equation:
x + y = -19
 y = -19-x

Insert y = -19-x in the first equation and solve for x:
x(-19-x)=88
-19x-x²=88
0=x²+19x+88
x²+19x+88=0 (Solve the quadratic equation)
(x+8)(x+11)=0

Therefore x=-8 or x=-11.

Plug in each x in any equations to get y:
When x=-8:
-8+y=-19
   y=-11

When x=-11
-11+y=-19
    y=-8
∴When x=-8, y=-11 and when x=-11, y=-8


Since in both situations the values of x and y are similar, the two numbers are -8 and -11.