Question

Which 6th term of an arithmetic progressions ap is -10 and its 10th term is -26 determine the 15 the term of an ap

Answer 1

Answer:

a+5d=-10

a+9d=-26

-4d=16

d=-4

a=-10

15th term=a+14d=-10+(-4×14)=-66

Answer 2

Answer:

a6 = a + 5d = -10 ------ equation 1

a10= a + 9d = - 26 -------equation 2

subtract equation 2 from 1

a + 5d = -10

-(a + 9d = -26)

-4d = 26

d = -13/2

NOW

PUT d IN EQUATION 1

a +5× -13/2 = -10

a = -10 +65/2

= 45/2

NOW

a 15 = a + 14 d

45/2 + 14 × 13/2

= 45/2 + 91

113.5