1) an = a1 + d*(n-1) => a20 = -4 + (-9)*19 = -4 - 171 = - 175
1) ---> C)
2) a81 = 20 + 4*80 = 340;
2) ---> A)
3) a12 = ?
3) ---> B) or D).
Answer:
Hence we prefer the distributive method when multiplying trinomial by a binomial.
Step-by-step explanation:
Explanation
- We have to explain when multiplying a trinomial by a binomial which method we prefer from the Distributive Property or the Vertical Method.
- We prefer the Distributive method because the method is the quickest than the vertical method methods as the vertical method has more steps than the distributive property also the vertical method is a bit complicated than the distributive method.
Since opposite angles and sides are equal, then the quadrilateral ABCD is a parallelogram.
Given that, ABCD is a quadrilateral, segment AB is congruent to segment CD, ∠1 is congruent to ∠2.
We need to prove that ABCD is a parallelogram.
<h3>
How to prove a given quadrilateral is a parallelogram?</h3>
If one pair of opposite sides of a quadrilateral are both parallel and congruent, then it’s a parallelogram.
From the given quadrilateral ABCD:
AB=CD (Given)
∠1=∠2 (Given)
AC=AC (Diagonal)
From ASA congruency ΔABC and ΔADC are congruent.
By CPCT, AD=BC and ∠ABC=∠ADC.
Since opposite angles and sides are equal, then the quadrilateral ABCD is a parallelogram.
To learn more about parallelogram visit:
brainly.com/question/1563728.
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