How do you solve for area and perimeter

Simplify 5 square root of 7 end root plus 12 square root of 6 end root minus 10 square root of 7 end root minus 5 square root of 6 . (1 point) 5 square root of 14 end root minus 7 square root of 12 5 square root of 7 end root minus 7 square root of 6 7 square root of 12 end root minus 5 square root of 14 7 square root of 6 end root minus 5 square root of 7

How do i do this activity, is appreciated

Acube has a volume of 800 cubic inches. whatis the length of an edge of the cube, in inches? a. 23/100b. 43/50c. 83/100d. 1003/2e. 1003/8