varible expressions

[lparker]

i know that a varible expressions are letters of the alphabet, also is used to represent the unknown. for example 3x squared - 5y +2xy- x-7 ok, how would you sovle this expressions if there is'nt a number to take the place of the varible? and if there were a number to take the place of the varibles i would have to multiply right?

 

[Deleted member 4993]

i know that a varible expressions are letters of the alphabet, also is used to represent the unknown. for example 3x squared - 5y +2xy- x-7 ok, how would you sovle this expressions if there is'nt a number to take the place of the varible? and if there were a number to take the place of the varibles i would have to multiply right?

Are trying to solve something like:

\(\displaystyle Ax^2 \, + \, Bx \, + \, C \, = \, 0\)

Please post the original problem - as opposed trying to express it verbally.

 

[Denis]

3x squared - 5y +2xy- x-7

If that's suppose to equal 0, then rewrite:
3x^2 + x(2y - 1) - 5y - 7 = 0
A=3, B=2y-1, C = -5y - 7
Solve for x using the quadratic formula.