It's 14. I don't understand if u are trying to test us or something like that because it's almost Christmas
Answer:
Step-by-step explanation:
Answer:
Step-by-step explanation:
<h3>AP given</h3>
<h3>To find</h3>
<h3>Solution</h3>
Common difference
<u>Difference of first two</u>
- d = (a -b) - (a + b) = -2b
<u>Difference of second two</u>
<u>Difference of last two</u>
<u>Now comparing d:</u>
- -2b = ab - (a - b)
- ab - a = - 3b
- a(1 - b) = 3b
- a = 3b/(1 - b)
and
- a/b - ab = -2b
- a(1/b - b) = -2b
- a = 2b²/(b² - 1)
<u>Eliminating a:</u>
- 2b²/(b² - 1) = 3b/(1 - b)
- 2b/(b+1) = -3
- 2b = -3b - 3
- 5b = - 3
- b = -3/5
<u>Finding a:</u>
- a = 3b/(1 - b) =
- 3*(-3/5) *1/(1 - (-3/5)) =
- -9/5*5/8 =
- -9/8
<u>So the first term is:</u>
- a + b = -3/5 - 9/8 = -24/40 - 45/40 = - 69/40
<u>Common difference:</u>
<u>The 6th term:</u>
- a₆ = a₁ + 5d =
- -69/40 + 5*6/5 =
- -69/40 + 240/40 =
- 171/40 = 4 11/40
