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3 years ago

The diagram shows a circle, centre O. Work out the value of a. BCO=41 degrees

Mathematics

1 answer:

sattari [20]3 years ago

5 0

Answer:

a = 49°

Step-by-step explanation:

OB = OC ( both radii of the circle ), thus

Δ BOC is isosceles and the base angles are congruent, that is

∠ OBC = ∠ OCB = 41° , so

∠ BOC = 180° - (2 × 41)° = 180° - 82° = 98°

The angle on the circumference BAC is half the angle at the centre for angles subtended on the same arc , thus

a = 0.5 × 98° = 49°

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Please help me with algebra part B and C. attachment below. Will mark as brainslist. 25 points.

miv72 [106K]

Answer:

C. $(-7x+60)(x+4)$

Step-by-step explanation:

Consider the expression $-7x^2+32x+240.$

First, note that

$a=-7\\ \\b=32\\ \\c=240$

Find the discriminant

$D=b^2-4ac=32^2-4\cdot (-7)\cdot 240=1,024+6,720=7,744\\ \\\sqrt{D}=\sqrt{7,744}=88$

Now,

$x_1=\dfrac{-b+\sqrt{D}}{2a}=\dfrac{-32+88}{2\cdot (-7)}=-4\\ \\x_2=\dfrac{-b-\sqrt{D}}{2a}=\dfrac{-32-88}{2\cdot (-7)}=\dfrac{60}{7}$

Write the factored form:

$-7x^2+32x+240=-7(x-(-4))\left(x-\dfrac{60}{7}\right)=(x+4)(-7x+60)$

8 0

3 years ago

A particular type of mold is growing 9.7% per hour. Assuming that mold growth continues at this rate and there were 14,000 spore

nydimaria [60]

Total mold spores at end of 9.30 am is 26901.

Step-by-step explanation:

Number of molds = 14000

Rate = 9.7% per hour

Number of hours = 12 am to 9.30 am = 9 $\frac{1}{2}$ hours

Growth of mold = 14000 * 9.7% * 9 $\frac{1}{2}$

= 12901

Total mold spores at end of 9.30 am = 14000 + 12901

= 26901

Hence, the expected number of mold spores at 9.30 am is 26901.

7 0

3 years ago

Which number have the same value as 20 tens

fomenos

The answer is 200. 20*10=200

6 0

3 years ago

Read 2 more answers

To make the chocolate shake, Dona added 40 mL of chocolate syrup,

Vsevolod [243]

Answer:

0.225 L of milk, would be required if she uses 450 m L of water.

Step-by-step explanation:

Here, to make the shake, ingredients used by Dina are:

40 m L of chocolate syrup,

200 m L of milk, and 400 m L of water.

So, here Amount of water used = 2 x ( Amount of Milk used) ....... (1)

Now,again the amount of water used by Dona = 450 m L

Let us assume the milk used by her = k m L

⇒ 450 m L = 2 x ( k m L) ( from (1))

or, 450 = 2 k

⇒ k = 450/2 = 225

⇒ k = 225 m L

Also, 1 m L = 0.001 L

So, 225 m L = 225 x 0.001 = 0.225 L

⇒ k = 0.225 L

Hence, 0.225 L of milk, would be required if she uses 450 m L of water.

5 0

4 years ago

Brine is a solution of salt and water. If a tub contains 50 gallons of a 5% solution of brine, how much water must evaporate to

vova2212 [387]

<span>Let x = amt of water evaporated :.05(50) = .08(50-x) 2.5 = 4 - .08x .08x = 4 - 2.5 .08x = 1.5 x = 18.75 lb of water evaporated : ; Check; amt of salt remains the same, only the percentage is different, right? .05(50) = .08(50-18.75) .05(50) = .08(31.25) 2.5 = 2.5</span>

7 0

3 years ago