calculate the difference between the sums of the first 10 terms of the arithmetic sequence 2,5,8 and 7,10,13
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Step-by-step explanation:
HAVE TO FIND THE DIFFERENCE BETWEEN THE SUM OF FIRST TEN'TH TERMS OF THE TWO GIVEN AP'S
FIRST SEQUENCE=2,5,8,11
A=2 D=3
REMEMBER IF THE FIRST TERM AND LAST TERM IS GIVEN SUM =
N(A+L)/2
WE HAVE TO FIND LAST TERM IE 10'TH TERM
10'TH TERM=A+9D=2+27=29
SUM= 10(2+29)/2 = 10*31/2=155--------------------------------(1)
SECOND SEQUENCE=7,10,13,16
A=7 D=3
10'TH TERM=A+9D=7+27=34
SUM= 10(7+34)/2=10*41/2=205--------------------------------(2)
DIFFERENCE=(2)-(1)
205-155=50
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