Is this correct? I'm not sure if I should add what x means..

Acamper leaves camp on a kayak and travels 50 miles east on a river, then he ties his kayak to the bank and travels 20 miles north on a bicycle. this trip can be plotted on the coordinate plane, where the camp is the point (0, 0). the distant of the camper to the camp can be found using the distance formula. which other formula can he use? a) 502 - 202 b) 502 + 202 c) 502 - 202 d) 502 + 202

3-12. write each answer with a reasonable number of figures. find the absolute uncertainty and percent relative uncertainty for each answer. (a) [12.41 (±0.09) + 4.16 (±0.01)] x 7.068 2 (±0.000 4) =? (b) [3.26 (±0.10) x 8.47 (±0.05)] - 0.18 (±0.06) =? (c) 6.843 (±0.008) x 104 + [2.09 (±0.04)- 1.63 (±0.01)] =?

Mozart lenses inc. recently introduced seelites, a thinner lens for eyelasses. of a sample of 800 eyeglass wearers, 246 said they would purchases their next pair of eyeglasses with the new lenses. lenses inc. estimates that the number of people who purchase eyeglasses in a year is 1,700,000. most eyeglasses wearer buy one new pair of eyeglasses a year. what is the annual sales potential for the new lenses.