NEED HELP ASAP

Choose Yes or No (for each one) to tell whether the expression represents a 20% discount off the price of an item that originally cost d dollars.
0.8d

d – 0.2

d – 0.2d

1 – 0.2d

Use the radius you found in part i (r=26.8 cm) with the surface area formula below to find the surface area of the sphere. show your work and round your answer to the nearest tenth. the surface area of a sphere: sa = 4πr^2 self note: 3.8.4

Liz had 140 pens and inna had 100 pens. after inna gave liz some pens, liz had 3 times as many pens as inna. how many pens did inna give liz?

Which expression is a perfect cube? a. x8 b. y24 c. m28 d. x64