Answer: 
Step-by-step explanation:
<u>The goal of the question</u>
Find the value of 2abcosC
<u>Given information</u>
a = 4
b = 3
c = 2
<u>Given formula (Law of Cosine)</u>

<u>Substitute values into the formula (Leave 2abcosC as it is)</u>

<u>Simplify the exponents</u>

<u>Simplify by addition</u>

<u>Add 2abcosC on both sides</u>


<u>Subtract 4 on both sides</u>


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Answer:
Step-by-step explanation:
800+20%
20%= (20/100)
800/100=8*20=160
add to original price= 800+160=960
The equation looks like this:
26=x*3.5+8.50
where x is the number of pen you bought.
We solve it like this:
first, we subtract 8.50 from both sides:
17.50 =3.5*x
now we divide both sides by 3.5:
5=x
so you purchased 5 pens.
Given: c | | d, m 4 = m 5
Prove: m 7 = m 8
1. c||d, m∠4=m∠5
GIVEN
2. m∠4 = m∠7
If lines ||, alternate interior angles are equal.
3. m∠5 = m∠8
Vertical angles are equal.
4. m∠7 = m∠8
Substitution