Robert is making pink paint by mixing red and white paint in the ratio 1:3. Red paint costs £5 for 500ml. White paint costs £8 for 3 litres. Plain tiles 40p ea Work out how much it will cost Robert to buy enough paint to make 12 litres of pink paint.

Idon't see any graph, however the graph of the function : f(x) = x²-2x+3 is a parabola: 1) open upward (since a> 0)2) it intersects y-axis in 3 (y=3)3) its axis of symmetry is x = +1 ( -b/2a)4) it's minimum is y = -2, so its vertex is (1,-2)5) it doesn't intersect the x-axis since discriminant < 0 

2x+10=36. x being the number of friends.