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prisoha [69]
3 years ago
5

3 Prove thatcos130°+cos 110+ cos10=0​

Mathematics
1 answer:
Evgesh-ka [11]3 years ago
5 0

We know, cos A + cos B = 2cos(C+D)/2 × cos(C - D)/2

So,

cos 130 + cos 110 + cos 10

cos 130 + 2cos (110+10)/2 × cos( 110-10)/2

cos 130 + 2cos 60 × cos 50

cos ( 180 - 50 ) + 2cos60 cos 50

We know, cos ( 180 - A ) = -cos A

2cos 60 cos 50 - cos 50

Also, cos 60 = 0.5

2×0.5 cos 50 - cos50

cos 50 - cos 50

0  = RHS.

Hence proved

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Evaluate the following expression:<br> 25x(x - 4) when x = -1
Arturiano [62]
Answer: 125

Explanation:
25x(x-4) when x = -1

25(-1)(-1-4)
= (-25)(-5)
= 125
3 0
3 years ago
How many solutions does -2z+2+4z=16/5+2z-6/5
kipiarov [429]

Answer:

Infinite. Please Mark Brainliest, this took a lot of effort.

Step-by-step explanation:

After going through the process of solving, you get 0=0, meaning true for all z

-2z+2+4z=16/5+2z-6/5

Group Like Terms

-2z+4z+2=16/5+2z-6/5

Add similar terms

2z+2=16/5+2z-6/5

Group Like Terms

2z+2=2z-6/5+16/5

<em>Combine the Fractions</em>

Apply the rule a/c plus or minus b over c equals a plus or minus b over c

=(-6+16)/5

Add/Subtract the numbers

=10/5

Divide the numbers

=2

2z+2=2z+2

Subtract 2 from each side

2z+2-2=2z+2-2

Simplify

2z=2z

Subtract 2z from each side

2z-2z=2z-2z

Simplify

0=0

Both sides are equal, true for all z

6 0
3 years ago
Brian is ordering T-shirts for the chess team. The team's budget for clothing is at most $60.
mrs_skeptik [129]
Brian can order 5 t-shirts for the chess team.

Explanation:

The question is basically asking you how many times can 12 fit in 60 without going over. To find the answer, divide 60 by 12, and you’ll get 5. Therefore, Brian can order 5 t-shirts.
7 0
3 years ago
Read 2 more answers
PLEASEEE HELPPP!!!<br> what is the reason for congruence
Ostrovityanka [42]

Answer:

ASA Hope this helped brainlest pls almost lvled up

Step-by-step explanation:

7 0
3 years ago
(10x²+19x+6) ÷(5x+2)​
Taya2010 [7]

Answer:

2x + 3

Step-by-step explanation:

(10x² + 19x + 6) ÷ (5x + 2)​ =

= (10x² + 15x + 4x + 6) ÷ (5x + 2)​

= [5x(2x + 3) + 2(2x + 3)] ÷ (5x + 2)​

= [(5x + 2)(2x + 3)] ÷ (5x + 2)​

= 2x + 3

7 0
3 years ago
Read 2 more answers
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