Answer:
a₁ = - 24
Step-by-step explanation:
The n th term of an AP is
= a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Given a₇ = 2a₅ , then
a₁ + 6d = 2(a₁ + 4d) = 2a₁ + 8d ( subtract 2a₁ + 8d from both sides )
- a₁ - 2d = 0 → (1)
The sum to n terms of an AP is
=
[ 2a₁ + (n - 1)d ]
Given = 84 , then
(2a₁ + 6d) = 84
3.5(2a₁ + 6d) = 84 ( divide both sides by 3.5 )
2a₁ + 6d = 24 → (2)
Thus we have 2 equations
- a₁ - 2d = 0 → (1)
2a₁ + 6d = 24 → (2)
Multiplying (1) by 3 and adding to (2) will eliminate d
- 3a₁ - 6d = 0 → (3)
Add (2) and (3) term by term to eliminate d
- a₁ = 24 ( multiply both sides by - 1 )
a₁ = - 24
Answer:
Please find attached the drawing of quadrilateral KLMN created with MS Whiteboard using the Ink to Shape command
(a) Two pairs of opposite sides are ,
and
,
(b) Two pairs of opposite angles are ∠LKN, ∠LMN, and ∠KLM and ∠KNM
(c) Two pairs of adjacent sides are ,
and
,
(d) Two pairs of adjacent angles are ∠LKN, ∠KLM and ∠LMN, ∠KNM
Step-by-step explanation:
