If AB=5y-4, BD=7y+3, AD=20y-9, find value of y

[Brittni123]

If AB = 5y - 4, BD = 7y + 3 and AD = 20y - 9, find the value of y.

 

[stapel]

If AB = 5y - 4, BD = 7y + 3 and AD = 20y - 9, find the value of y.

What is the relationship between A, B, and D? Is there any "C" involved somewhere? How many different lines (or segments) are involved here? What have you tried? Where are you stuck?

Please be complete. Thank you! :wink:

 

[soroban]

Hello, Brittni123!

A little explanation would have helped . . .

\(\displaystyle \text{If }AB \:=\; 5y - 4,\; BD \:=\: 7y + 3,\text{ and }AD \:=\: 20y - 9,\,\text{ find the value of }y.\)

Here's one interpretation . . .

      : - - -  20y-9  - - - - - :
      *----------*--------------*
      A - 5y-4 - B - - 7y+3 - - D

 

[mmm4444bot]

Another interpretation (system of three equations in four unknowns A, B, D, and y):

y = 4/5 + B/5 * [roots of quadratic polynomial in z: 7B z^2 + (43 - 20B^2) z - 35B]