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3 years ago

Can some one please help with this question

Mathematics

1 answer:

Rudiy273 years ago

6 0

Answer:

5x + 9

Step-by-step explanation:

f(x) = 3x+4

g(x) = 2x + 5

(f+g)(x)

(3x+4) + (2x + 5)

= 5x + 9

// however I'm unsure

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What value of n solves the equation 3n=1/81 N=___

Radda [10]

3n = 1/81; divide both sides by 3 to isolate n:

3n/3 = 1/81 divided by 3. Remember that when you divide, you use the reciprocal and multiply instead!!

n = 1/81(1/3) = 1/243. Now plug 1/243 back in for n, and 3/243 is equivalent to 1/81

7 0

3 years ago

Is 2.4, 4.5 and 5.2 a right triangle?

grandymaker [24]

Answer:

Step-by-step explanation:

Use the pythagorian theorm to find whether it's a right triangle or not.

So the hyp will be the largest number. And the hyp must be equal to the sum of b and c squared

5.2 squared= 2.4 squared+ 4m5 squared

27.04= 26.01

It's not equal so the triangle isn't a right triangle.

3 0

2 years ago

Courtney walked from her house to the beach at a constant speed of 4 kilometers per hour, and then walked

RUDIKE [14]

The system of equations that represents this situation are:

q + p = 2

4q + 5p = 8

Solution:

Let q be the number of hours it took Courtney to walk from her house to the beach

Let p be the number of hours it took her to walk from the beach to the park

The entire walk took 2 hours

Therefore,

q + p = 2 ------- eqn 1

The total distance Courtney walked was 8 kilometers

Total distance = 8 km

Courtney walked from her house to the beach at a constant speed of 4 kilometers per hour

Then walked from the beach to the park at a constant speed of 5 kilometers per hour

Distance is given as:

$distance = speed \times time$

From her house to the beach:

$distance = 4 \times q = 4q$

From the beach to the park:

$distance = 5 \times p = 5p$

We know that,

Total distance = 8 km

Therefore,

4q + 5p = 8 ------ eqn 2

Thus the system of equations that represents this situation are:

q + p = 2

4q + 5p = 8

8 0

4 years ago

At 7:00 A.M., Alicia pours a cup of tea whose temperature is 200°F. The tea starts to cool to room temperature (72°F). At 7:02 A

NeTakaya

Answer:

Part A

The most correct option is;

b. y = 128(0.989)x + 72

Part B

Ella can drink the tea after 7:22

Step-by-step explanation:

Here we have the temperature variation with time given in an exponential equation as follows;

Let the temperature at time x (in minutes) = y

Therefore, y = a × mˣ + b

Where:

b = Shift of the curve or the limit value of the decreasing exponential function as x → ∞

When y = 200, x = 0

Therefore. 200 = a × m⁰ + c = a + c

We note that c is the shift of the graph, the value upon which temperature increases = final temperature = 72°F

Hence a = 200 - 72 = 128°F

When y = 197, x = 2 minutes

Therefore, 197 = 128·m² + 72 =

m² = (197 - 72)/128 = 125/128

m = √(125/128) = 0.98821

Hence the exponential equation of cooling is presented in the following equation;

y = 128 × (0.98821)ˣ + 72

Therefore, the most correct option is b. y = 128(0.989)x + 72

Part B

When the temperature is 172°F we have;

172 = 128 × (0.989)ˣ + 72

∴ (0.989)ˣ = (172 - 72)/128 = 100/128 = 25/32

log(0.989)ˣ = log(25/32)

x·log(0.989) = log(25/32)

x = log(25/32)/log(0.989) = 22.32 minutes

Hence Ella can drink the tea after 7:22.

6 0

3 years ago

The size of angle aob is equal to 132 degrees and the size of angle cod is equal to 141 degrees. find the size of angle dob.

Varvara68 [4.7K]

angle AOB = 132 and is also the sum of angles AOD and DOB. Hence
angle AOD + angle DOB = 132°    ---> 1

angle COD = 141 and is also the sum of angles COB and BOD. Hence
angle COB + angle DOB = 141°    ---> 2

Now we add the left sides together and the right sides of equations 1 and 2 together to form a new equation.

angle AOD + angle DOB + angle COB + angle DOB = 132 + 141       ---> 3

We should also note that:
angle AOD + angle DOB + angle COB = 180°

Therefore substituting angle AOD + angle DOB + angle COB in equation 3 by 180 and solving for angle DOB:
180 + angle DOB = 132 + 141
angle DOB = 273 - 180 = 93°

8 0

3 years ago