Question

if the sum of three numbers in A P is 12and sum of their cubes is 408, find the number
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Answer 1

Step-by-step explanation:

shoutcut method

sum of thee no. is 4a

4a= 12

a=3

also cube of these no. is

3a^3+2(2ad^2)= 408

put a=3

3×27+2(6d^2)408

81+12d^2=408

12d^2=408-81

now you also solve