4a+2 because you divide 16a+8 by 4 because a square has 4 sides
76 cm,
(4•10=40)+((10-4)•6)= 76 units
For multiplying fractions you basically just multiply across so for the green one it would be 1x4=4 so you would have 4 as the numerator for the answer and the bottom is 2x8=16 so that would be the denominator your answer would be 4/16 for the green question