Please explain me all these questions step by step with the answers.

Problem 6. (10 points) 1. The radius of a spherical ba loon l/ati/2centimeters per minute, fast is the surface area changing iAhen the radius {is (21entimefehs? Hint: The surface area ISA Rate of change Of surface area - 2. The surface area 011 a spherical' ballon i ,ine asih atliate, Of 86 centimeters squared per minute. Fbwfast is the radius changing when the radius Gis 14 cen 'imeteks? Rate of change Of radius Note: You can earn partial credit on th s problem preview an-suers Problem 7. (15 points) A landscape architect wished to enclose a rectangular garden on one side by a brick wall costing $30/ft and on the other three sides by a metal fence costing $1 Olft, If the area of the garden is 188 square feet, find the dimensions of the garden that minimize the' COG Length of side Wth bricks a: Length of adjacent side Note: You can earn par"/ credft -on! ih -s problem preview answers Remaining time: 118110 (min:sec) Problem 8. (10 points) Let y ($2 + 1)5. Find the differential dy Bhen 2 end Find the differential dy Mien at 2 and Note: You can earn partial credit on this