(b) is relatively easy. Since there is no middle term, the graph is that of a parabola with vertex at (0, -9), opening downward due to the (-) sign
In (a), we have 3x^2-18x+27 = f(x). 3 can be factored out: f(x) =3(<span>x^2-6x+9).
Can you see that this is already a perfect square? So f(x) = 3(x-3)^2 + 0.
The vertex is at (3, 0). Place a black dot at that point on graph paper. Because the leading coeff. of </span><span>3x^2-18x+27 is +, the parabola opens UP. The y-intercept is found by letting x=0: f(0) = 3(0)^2 - 18(0) + 27 => (0,27).</span>
Cost of airplane toy = $4.84 let x be the cost of the toy car cost of airplane toy is 4 times the cost of toy car; it means 4x = $4.84 x = 4.84 / 4 x = 1.21 Thus, the cost of toy car is $1.21.