1. The polynomial G(x) = -0.006x4 + 0.140x3 - 0.53x2 + 1.79x measures the concentration of a dye in the bloodstream x seconds after it is injected. Does the concentration increase between 12 and 13 seconds?
2. The time T necessary to make an enlargement of a photo negative varies directly as the area A of the enlargement. If 168 seconds are required to make a 3-by-7 enlargement, find the time required for a 5-by-10 enlargement.