Standard form for a parabola: ( x - h )² = 4 p ( y - k ) Vertex: ( h, k ) = ( -4, 2 ) Displacement from vertex to focus: p = 2/8 = 1/4 ( x + 4 )² = 4 · 1/4 ( y - 2 ) y = ( x + 4 )² + 2 or general form: x² + 8 x - y + 18 = 0
To work out how much Luz earns, you simply have to follow 400/40=10, so
she earns $10/hour. We can therefore establish that if she works for 6
hours, she'll earn $60.