the negative number would most likely be -19/2
let the negative number be x,
3 less than twice that negative number would be (2x-3)
hence,
equation form
x multiply by (2x-3) equals to 209
it would result in equation
2x^2-3x=209
2x^2-3x-209=0
hence using quadratic eqn
x=11 ( rej since qn stated x is a negative number)
x=-19/2