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3 years ago

What is 2/3x+4=4/5x-2

Mathematics

2 answers:

Anuta_ua [19.1K]3 years ago

8 0

Hey there!

Apply fraction cross multiply: if a/b = c/d , then a *d = b*c

2 ( 5x - 2 ) = ( 2x + 4 ) * 4

expand : 2 (5x-2 ) => 2*5x - 2*2 => 10x - 4

expand : ( 2x +4 ) * 4 => 2x * 4 + 4*4 => 8x + 16

10x - 4 = 8x+16

add 4 to both sides:

10x-4+4 = 8x+16+4

simplify :

10x = 8x + 20

subtract 8x from both sides:

10x -8x = 8x+20-8x

simplify:

2x = 20

Therefore:

x = 20 / 2

x = 10

Hope that helps!

White raven [17]3 years ago

4 0

Step 1. Simplify 2/3x to 2x/3

2x/3 + 4 = 4/5x - 2

Step 2. Simplify 4/5x to 4x/5

2x/3 + 4 = 4x/5 - 2

Step 3. Multiply both sides by 15 (the LCM of 3,5)

10x + 60 = 12x - 30

Step 4. Subtract 10x from both sides

60 = 12x - 30 - 10x

Step 5. Simplify 12x - 30 - 10x to 2x - 30

60 =2x - 30

Step 6. Add 30 to both sides

60 + 30 =2x

Step 7. Simplify 60 + 30 to 90

90 = 2x

Step 8. Divide both sides by 2

90/2 = x

Step 9. Simplify 90/2 to 45

45 = x

Step 10. Switch sides

x = 45

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3 years ago

If bolt thread length is normally distributed, what is the probability that the thread length of a randomly selected bolt is Wit

KatRina [158]

Answer:

a) 0.5762

b) 0.0214

c) 0.2718

Step-by-step explanation:

It is given that lengths of the bolt thread are normally distributed. So in order to find the required probability we can use the concept of z distribution and z scores.

Part a) Probability that length is within 0.8 SDs of the mean

We have to calculate the probability that the length of a bolt thread is within 0.8 standard deviations of the mean. Recall that a z- score tells us that how many standard deviations away a value is from the mean. So, indirectly we are given the z-scores here.

Within 0.8 SDs of the mean, means from a score of -0.8 to +0.8. i.e. we have to calculate:

P(-0.8 < z < 0.8)

We can find these values from the z table.

P(-0.8 < z < 0.8) = P(z < 0.8) - P(z < -0.8)

= 0.7881 - 0.2119

= 0.5762

Thus, the probability that the thread length of a randomly selected bolt is within 0.8 SDs of its mean value is 0.5762

Part b) Probability that length is farther than 2.3 SDs from the mean

As mentioned in previous part, 2.3 SDs means a z-score of 2.3.

2.3 Standard Deviations farther from the mean, means the probability that z scores is lesser than - 2.3 or greater than 2.3

i.e. we have to calculate:

P(z < -2.3 or z > 2.3)

According to the symmetry rules of z-distribution:

P(z < -2.3 or z > 2.3) = 1 - P(-2.3 < z < 2.3)

We can calculate P(-2.3 < z < 2.3) from the z-table, which comes out to be 0.9786. So,

P(z < -2.3 or z > 2.3) = 1 - 0.9786

= 0.0214

Thus, the probability that a bolt length is 2.3 SDs farther from the mean is 0.0214

Part c) Probability that length is between 1 and 2 SDs from the mean value

Between 1 and 2 SDs from the mean value can occur both above the mean and below the mean.

For above the mean: between 1 and 2 SDs means between the z scores 1 and 2

For below the mean: between 1 and 2 SDs means between the z scores -2 and -1

i.e. we have to find:

P( 1 < z < 2) + P(-2 < z < -1)

According to the symmetry rules of z distribution:

P( 1 < z < 2) + P(-2 < z < -1) = 2P(1 < z < 2)

We can calculate P(1 < z < 2) from the z tables, which comes out to be: 0.1359

So,

P( 1 < z < 2) + P(-2 < z < -1) = 2 x 0.1359

= 0.2718

Thus, the probability that the bolt length is between 1 and 2 SDs from its mean value is 0.2718

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3 years ago

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STatiana [176]

Answer:

Step-by-step explanation:

There are 2 very distinct and important things that we need to know before completing the problem. First is that we are given that the cos of an angle is 1/3 (adjacent/hypotenuse) and it is in the first quadrant. We also need to know that the identity for sin2θ = 2sinθcosθ.

We already know cos θ = 1/3, so we need now find the sin θ. The sin ratio is the side opposite the angle over the hypotenuse, and the side we are missing is the side opposite the angle (we do not need to know the angle; it's irrelevant). Set up a right triangle in the first quadrant and label the base with a 1 (because the base is the side adjacent to the angle), and the hypotenuse with a 3. Find the third side using Pythagorean's Theorem:

$3^2=1^2+y^2$ which simplifies to