Iwill mark your as brainliest or what ever and 10 points

Question 20

Total Surface Area = (4 x 8) + (5 x 8) + (8 x 3) +  2(1/2 x 4 x 3)
Total Surface Area = 108 cm²

Question 21

Total Surface Area = 2 (π x 4²) + (π x (4x2) x 20 ) 
Total Surface Area = 603 cm² (Nearest whole number)

Question 22

Total Surface Area = (20 x 5) + (12 x 20) + (20 x 13) + 2 ( 1/2 x 12 x 5)
Total Surface Area = 660 In²

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.

This is what i found “an explicit formula designates the nth term of the sequence, as an expression of n (where n = the term's location). it defines the sequence as a formula in terms of n. this example is an arithmetic sequence(the same number, 5, is added to each term to get to the next term).” i hope this you for what your looking for. can you plz mark me brainliest?