Question

calculate the difference between the sums of the first 10 terms of the arithmetic sequence 2,5,8 and 7,10,13​

Answer 1

Answer:

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