# math

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in an ap the difference is between the 8th and 4th term is 20 and the 8th term is one and the half times the fourth term what is the common difference

• math -

since T8 = T4+4d, d=5

and, just for completeness,

a+7d = 3/2 (a+3d)
a+35 = 3/2 (a+15)
2a+70 = 3a+45
a=25

So, the sequence is

25 30 35 40 45 50 55 60 ...

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