Question 1085962
Discriminant must be 0.


{{{16^2-4*9*c=0}}}
{{{4*4*16-4*9c=0}}}
{{{4*16-9c=0}}}
{{{9c=4*16}}}
{{{c=(4*16)/9}}}
{{{highlight(c=64/9)}}}






-------------------------------
---MISTAKE---
{{{16^2-4*9*16*c=0}}}----mistake
{{{16+36c=0}}}
{{{8+18c=0}}}
{{{4+9c=0}}}
{{{9c=-4}}}
{{{cross(c=-4/9)}}}