Welcome to our community

Be a part of something great, join today!

[SOLVED] Algeb

Sudharaka

Well-known member
MHB Math Helper
Feb 5, 2012
1,621
srirahulan's question titled "Algeb" from Math Help Forum,

If \(ax^2+2x+1=0\mbox{ and }x^2+2x+a=0\) have the common roots, find the real value of a.
Hi srirahulan,

Let \(\alpha\mbox{ and }\beta\) be the two roots of these quadratic equations. Then, according to the first equation,

\[\alpha+\beta=-\frac{2}{a}~~~~~~(1)\]

Considering the second equation,

\[\alpha+\beta=-2~~~~~~~(2)\]

By (1) and (2);

\[-\frac{2}{a}=-2\]

\[\therefore a=1\]