Two numbers are 10 units away in different directions from their midpoint, m, on a number line. The product of the numbers is -99. Which equation can be used to find m, the midpoint of the two numbers?

Respuesta :

Answer:

[tex]m = \dfrac{a^2-99}{2a}[/tex]

Step-by-step explanation:

on a number line, m is the point that is the midpoint of two other points.

the distance between each of the points to the midpoint is 10 units..

if a is the point 10 units less than m

and b is the point 10 units greater than m,

then,

[tex]m = a+10[/tex]

[tex]m = b-10[/tex]

we can add the two equations to form the midpoint formula.

[tex]2m = a+b[/tex]

we also know that the product of both numbers equal -99.

[tex]ab = -99[/tex]

we can substitute either 'a' or 'b' to the equation of m.

[tex]2m = a-\dfrac{99}{a}[/tex]

[tex]m = \dfrac{a^2-99}{2a}[/tex]

and this is the equation for the midpoint of the two numbers.

Answer:

c

Step-by-step explanation: