Question

the fifth term of an A.P is 26 and it's 10th term is 51.find the 1st term. class 10

Answer 1

a5= a+(5-1)d
26=a+4d------> 1

a10=a+(10-1)d
51=a+9d------> 2

by elimination method

a+9d=51
a+4d=26
(-)(-)=(-)
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5d=25
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d=25/5
d=5
a+4(5)=26
a+20=26
a=26-20
a=6
firat term=6

Answer 2

Answer:a5= a+(5-1)d

26=a+4d------> 1

a10=a+(10-1)d

51=a+9d------> 2

by elimination method

a+9d=51

a+4d=26

(-)(-)=(-)

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5d=25

-------------

d=25/5

d=5

a+4(5)=26

a+20=26

a=26-20

a=6

firat term=

Step-by-step explanation: