The 7th term of an AP is 4 times its 2nd term and 12 th term is 2 more than 3 times of its 4th term find progression
Answers
Answer:
2,5,8,..
Step-by-step explanation:
Solve by following the process I have shown. Hope it helps you
The progression is :2,5,8,11,14,17
The 7th term of an AP is four times its 2nd term.
12th term is two more than three times its 4 th term.
The progression.
First term of an AP = a
Common difference = d
⟹Tn = a +(n - 1)×d⟹Tn=a+(n−1)×d
Tn = nth term
a = First term
n = Number of terms
d = Common difference
The seventh term of an AP is four times its 2nd term.
⟹T₇ = 4 T₂
⟹a + (7 - 1)d = 4{a+(2 -1)d}
⟹a + 6d = 4{a+d}
⟹4a - a = 6d - 4d
⟹3a = 2d_______(i)
12th term is 2 more than three times of its 4th term.
⟹T₁₂ = 3T₄ + 2
⟹a + (12 - 1) d =3{a + (4 - 1)d}+2
⟹a+11d = 3{a +3d}+2
⟹a + 11 d = 3a + 9d + 2
⟹11d - 9d = 3a - a + 2
⟹2d = 2a + 2⠀⠀⠀⠀ [From eqⁿ (i)2d = 3a]
⟹3a = 2a + 2
⟹3a - 2a = 2
⟹a = 2
⠀⠀⠀⠀First term= 2
In equation (i),
⟹2d = 3a
⟹2d = 3×2⠀⠀⠀⠀⠀ [ The value of a = 2]
⟹2d = 6
⟹d = 3
⠀⠀⠀⠀Common difference = 3
⟹T₁ = a = 2
⟹T₂ = a + d = 2 + 3 = 5
⟹T₃ = a + 2d = 2 + 6 = 8
⟹T₄ = a + 3d = 2 + 9 = 11
⟹T₅ = a + 4d = 2 + 12 = 14
⟹T₆ = a + 5d = 2 + 15 = 17