Bonsoir je galère un peu à faire cet exercice pouvez vous m'aidez svp

Data: AB = 1170 m and BC = 1080 m. 1) Bob lives in New York, at the corner of 72nd street and Broadway (A). He works at the end of Broadway 5(B). To go to work, he usually walks down Broadway. But since Monday, in order to get more exercise, he's been walking down 72nd street and along Central Park. How many extra meters does Bob walk every day? (Calculate AC and compare AB and AC + CB!)

2) He says that the temperature on Christmas' day was T = -4 + 4 × 6 ÷ (-17 + 15) - 2 × (-5) in °C. Calculate T.​