$3x(x+5) + 2(2x-5) = ax^2+bx+c$ <br> In the above equation, $a, \; b$ and $c$ are constants. If the equation is true for all values of $x$, then what is the value of $c$ ?

Question

$\begin{array}{1 1} (a)\; -10 \\ (b)\; 10 \\ (c) -5\\ (d)\; 5 \end{array}$