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3 years ago

In △ABC,a=11 , b=20 , and c=28 . Find m∠A .

Mathematics

1 answer:

Helga [31]3 years ago

4 0

Answer:

18.4°

Step-by-step explanation:

Use law of cosine.

a² = b² + c² − 2bc cos A

11² = 20² + 28² − 2(20)(28) cos A

121 = 1184 − 1120 cos A

cos A = 0.949

A = 18.4°

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What are the factors of 3x2 + 10x + 8?

vivado [14]

Answer: (3x+2)(x+4)

Step-by-step explanation:Explanation:

3x2+10x−8

first multiply

with −8

and we get −24

then find two numbers that if we add or subtract we get

+10

and if we multiply we get

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and the numbers are

+12

and

−2

then we place those numbers as follow :-

3x2+12x−2x−8

then we group them

(3x2+12x)(−2x−8)

now take the common factor out.3x(x+4)−2(x+4)

then group the numbers outside of the brackets

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2 years ago

A table is on sale for 65% off. the sale price is $154 . what is the regular price?

Yuliya22 [10]

The original price is $254.10 or 254 rounded. 154 times .65 is 100.1. Add 100.1 to the sale price which is 154 and you'll get the original, 254.
Hope this helps :)

7 0

3 years ago

A town is planning a playground. It wants to fence in a rectangular space using an existing wall. What is the greatest area it c

777dan777 [17]

Answer:

1250 $ft^{2}$

Step-by-step explanation:

We are given that the playground is fenced on three sides of the playground and the four side has an existing wall.

Let the length of the rectangle be 'X' feet and width be 'Y' feet.

As the fencing is done using 100 feet of fence. We get the relation between the sides and the fence as, X + 2Y = 100.

As, X + 2Y = 100 → X = 100 - 2Y

Now, the area of the rectangle = XY = X × ( 100 - 2Y ).

i.e Area of the rectangle = $-2Y^{2} +100Y$ .

The general form of a quadratic equation is $y=ax^{2}+bx+c$ .

The maximum value of a quadratic equation is given by $x=\frac{-b}{2a}$ .

Therefore, the greatest value of $-2Y^{2} +100Y$ is at Y = $\frac{-100}{2 \times -2}$ = $\frac{-100}{-4}$ = 25.

Thus, Y = 25 and X = 100 - 2Y → X = 100 - 2 × 25 → X = 50.

Hence, the area of the rectangle is XY = 50 × 25 = 1250 $ft^{2}$ .

3 0

3 years ago

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Olegator [25]

Congruent
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5 0

3 years ago

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snow_lady [41]

Answer:

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Step-by-step explanation:

8 0

2 years ago