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3 years ago

Which expressions are equivalent to 22c + 33d?

Mathematics

1 answer:

harkovskaia [24]3 years ago

4 0

Answer:

A, C, and E

Step-by-step explanation:

For the first one, distribute -11 to each value. A negative times a negative is a positive, so -11×-2c is 22c. -11×-3d is 33d. So the first one is right. For the third one, distribute 1/3 to each value. 1/3 of 66c is 22c, and 1/3 of 99d is 33d, so the third one is correct as well. For the last one, distribute 11 again. 11×2c is 22c and 11×3d is 33d, so the last one is correct.

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H+p=4(k−7) for k please answer

dmitriy555 [2]

Answer:

(28 + h + p)/4 = k

Step-by-step explanation:

Step 1: Write equation

h + p = 4(k - 7)

Step 2: Solve for k

Distribute 4: h + p = 4k - 28

Add 28 to both sides: 28 + h + p = 4k

Divide both sides by 4: (28 + h + p)/4 = k

3 0

3 years ago

A person takes a trip, driving with a constant peed of 89.5 km/h, except for a 22.0-min rest stop. If the peron's average speed

Stolb23 [73]

Answer:

a) The person traveled 2.83 hours.

b) The person travels 220.17 kilometers.

Step-by-step explanation:

We have that the speed is the distance divided by the time. Mathematically, that is

$s = \frac{d}{t}$

(a) how much time is spent on the trip and

The peron's average speed is 77.8 km/h, which means that $s = 77.8$

The person distance traveled is:

22 min is 22/60 = 0.37h.

So for the time t1, the person traveled at a speed of 89.5 km/h. Which has a distance of 89.5*t1.

For 0.37h, the person was at a stop, so she did not travel. This means that the total distance is

$d = 89.5t1 + 0 = 89.5t1$

The total time is the time traveling t and the stoppage time 0.37. So

$t = t1 + 0.37$

We want to find t1, which is the time that the person was driving.

$s = \frac{d}{t}$

$77.8 = \frac{89.5t1}{t1 + 0.37}$

$77.8t1 + 77.8*0.37 = 89.5t1$

$11.7t1 = 28.786$

$t1 = \frac{28.786}{11.7}$

$t1 = 2.46$

The total time is

$t = t1 + 0.37 = 2.46 + 0.37 = 2.83$

The person traveled for 2.83 hours.

(b) how far does the person travel?

The person traveled 2.46 hours at an average speed of 77.8 km/h. So

$s = \frac{d}{t}$

$77.8 = \frac{d}{2.83}$

$d = 77.8*2.83 = 220.17$

The person travels 220.17 kilometers.

8 0

3 years ago

Root 3 cosec140° - sec140°=4 prove that

Lorico [155]

Answer:

Step-by-step explanation:

We are to show that $\sqrt{3} cosec140^{0} - sec140^{0} = 4\\$

Proof:

From trigonometry identity;

$cosec \theta = \frac{1}{sin\theta} \\sec\theta = \frac{1}{cos\theta}$

$\sqrt{3} cosec140^{0} - sec140^{0} \\= \frac{\sqrt{3} }{sin140} - \frac{1}{cos140} \\= \frac{\sqrt{3}cos140-sin140 }{sin140cos140} \\$

From trigonometry, 2sinAcosA = Sin2A

$= \frac{\sqrt{3}cos140-sin140 }{sin140cos140} \\\\= \frac{\sqrt{3}cos140-sin140 }{sin280/2}\\= \frac{4(\sqrt{3}/2cos140-1/2sin140) }{2sin280}\\\\= \frac{4(\sqrt{3}/2cos140-1/2sin140) }{sin280}\\since sin420 = \sqrt{3}/2 \ and \ cos420 = 1/2 \\ then\\\frac{4(sin420cos140-cos420sin140) }{sin280}$