Answer :
Given that the base of the triangle is x m, the height is 3m less than twice it's base then the height will be represented by the equation:
(2x-3) m
Thus the area will be:
Area=1/2bh
Area=1/2x(2x-3)=17.5
x^2-1.5x=17.5
Writing the above equation is quadratic form of ax^2+bx+c=0 we get:
x^2-1.5x-17.5=0