Question

ques 7 a of ap solve it quickly

Answer 1

Answer:

Step-by-step explanation:

a₁₄ =  2a₈ ......(A)

a₆ = (-8)

A:

a₆ + 8d = 2(a₆ + 2d)

a₆ + 8d = 2a₆ + 4d

8d - 4d = 2a₆ - a₆

a₆ = 4d

4d = (-8)

d = (-8)/4

d = (-2)

a = a₆ - 5d

a = (-8) + 10

a = 2

Sn = n/2 x (2a + (n-1)d)

20/2 x (4 + (20-1)(-2))

10 x (4 -38)

10 x (-34) = (-340)

Answer 2

So by finding a and d from the given equations we have solved the above mentioned question.