what two numbers add up to -23 and multiply to make 120?

10 Answers

  • (-8) + (-15) = -23

    and

    (-8) (-15) = +120

    1) Form equations and solve to get the answer.

    Here, the eqns are x + y = -23 and xy = 120

    y = -23 -x

    Sub in the other as x(-23-x) = 120

    -23x-x^2 = 120

    x^2 + 23x + 120 = 0

    Solution for this is

    x = [ -23 + sqrt{23^2 - 4(1)(120)} ]/2 and

    x = [ -23 - sqrt{23^2 - 4(1)(120)} ]/2

    Solve and u'll get -8 and -15

    2) Trial & Error

    120 = 12 * 10

    = 4 3 5 * 2

    = 4 ( 3 5) * 2 ---> Combine suct that their sum is 23.

    = (42) (35)

    = 8 * 15 --->8+15=23

    Since the req. 2 nos. add to give -23, ur answer should be negative.

    Therefore, -8 and -15

    It is known that multiplication of 2 negative nos. yields a positive number.

  • Many of these types of problems are trial and error.

    First, what two numbers add up to -23 that are fairly big numbers (since they have to make a large number: 120).

    After trial and error, I figured out it is -8 and -15.

    Hope that helps!

  • x + y = -23

    xy = 120

    x( -23 - x) = 120

    -23x - x^2 = 120

    0 = x^2 + 23x + 120

    0 = (x + 15)(x + 8)

    x = -15 or x = -8

  • x+y=-23 ==> y=-x-23

    xy=120

    x(-x-23)=120

    x^2+23x+120=0

    Solve for quadratic equation:

    [-23+/- sqrt(23^2-4(1)(120))]/2

    x = -15, y = -8

  • What Two Numbers

  • X + Y = -23

    X times Y = 120

    Use this system of equation to solve.

    you will get -15 and -8

  • -8 and -15

  • -15 and -8

  • x= first number

    y= second number

    1st equation x+ y = -23 or y= -23-x

    2nd equation x*y= 120

    Substituting 1 in 2

    .... x times (-23-x)= 120

    Now please solve the quadratic equation and find the x. If nobody does iyt for you and you cant e-maill me

  • x+y=-23

    x=-23-y

    Also

    xy=120

    so substitute the -23-y for x and you get

    y(-23-y) =120

    y^2-23y=120

    Then use the quadratic formula.

    x is plus or minus 11.5,

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