Question 6If $c$ is a real number and the negative of one of the solutions of $x^2-3x+c=0$ is a solution of $x^2+3x-c=0,$ then the solutions of $x^2-3x+c=0$ are$1,$ $2$$-1,$ $-2$$0,$ $3$$0,$ $-3$$\frac32,$ $\frac32$