Answer
$x=-.24$
Work Step by Step
We are given the equation $9x+1.6=4x+.4$.
In the next step, this equation is incorrectly simplified to $5x=1.2$.
The correct way to simplify the equation is to first subtract 4x from both sides.
$5x+1.6=.4$
And then subtract 1.6 from both sides.
$5x=-1.2$
Divide both sides by 5.
$x=-.24$