I am going to assume 2.5x is really 25x (typo).
First formulate the equality
[tex]
4x^2-16x+25x=0 \\
4x^2+9x=0 \\
x(4x+9)=0 \\
[/tex]
Now two results emerge.
[tex]x_1=0, x_2=-\dfrac{9}{4}[/tex].
Hope this helps.
