What’s twice the difference of a number and 8 is at least -20 using x as a variable into a inequality please help!!!

Prove that the gregorian calendar repeats itself every 400 years.

Setler79 [48]

The calendar obviously has an integral number of years and months in 400 years. If it has an integral number of weeks, then it will repeat itself after that time. The rules of the calendar eliminate a leap year in 3 out of the four century years, so there are 97 leap years in 400 years. The number of excess days of the week in 400 years can be found by ...

(303·365) mod 7 + (97·366) mod 7 = (2·1 + 6·2) mod 7 = 14 mod 7 = 0

Thus, there are also an integral number of weeks in 400 years.

The first day of the week is the same at the start of every 400-year interval, so the calendar repeats every 400 years.

3 0

3 years ago

Anybody know!!!! SOS

ikadub [295]

Answer:

x = 50

Step-by-step explanation:

The sum of the measures of the interior angles of a polygon of n sides is

(n - 2)180

This polygon is a quadrilateral with 4 sides. n = 4

(n - 2)180 = (4 - 2)180 = 2(180) = 360

The sum of the measures of the interior angles of the quadrilateral is 360 degrees.

We have angles of 110 deg, 2x deg, x + 10 deg, and 90 deg. We add their measures and set teh sum equal to 360. Then we solve for x.

x + 10 + 2x + 110 + 90 = 360

3x + 210 = 360

3x = 150

x = 50

4 0

2 years ago

Read 2 more answers

Two trains start from Fort Worth traveling at the same speed. The trip for Train W takes 20 hours, while the trip for Train Z ta

MrMuchimi

Answer:

The equation that best models this situation is :

b. $\frac{x}{20}=\frac{x+400}{25}$

Distance traveled by Train W = 1600 miles

Distance traveled by Train Z = 2,000 miles

Step-by-step explanation:

Given:

Time taken for Train W to complete a trip = 20 hours

Time taken for Train Z to complete a trip = 25 hours

The city Train Z is traveling to is 400 miles farther away than the city Train W is traveling to.

both trains have same speeds and start from same location.

To find the distance in total each train travels.

Solution:

<em>Let length of the trip of Train W be </em>= $x$ miles

Speed of Train W can be given as :

⇒ $\frac{Distance}{Time}$

⇒ $\frac{x}{20}\ miles/h$

<em>So, the length of the trip of Train Z will be</em> = $(x+400)$ miles

Speed of Train Z can be given as :

⇒ $\frac{Distance}{Time}$

⇒ $\frac{x+400}{25}\ miles/h$

Since the speeds are same, so the equation to find $x$ can be given as:

⇒ $\frac{x}{20}=\frac{x+400}{25}$

Solving for $x$

Multiplying both sides by 100 to remove fractions.

⇒ $100\times \frac{x}{20}=100\times \frac{x+400}{25}$

⇒ $5x=4(x+400)$

Using distribution.

⇒ $5x=4x+1600$

Subtracting both sides by $4x$

⇒ $5x-4x=4x-4x+1600$

⇒ $x=1600$

Thus, Distance traveled by Train W = 1600 miles

Distance traveled by Train Z = $1600+400$ = 2,000 miles

3 0

3 years ago

can you please explain to me how 570ml = oz. I'm having a hard time figuring it out. I'm having a problem with converting.

Vladimir79 [104]

19.2740122 fluid ounces = 570 milliliters. I'm positive this really is the answer. :)

8 0

3 years ago

Please help! I’ll give brainliest

Vilka [71]

Answer:

Step 1: Simplify both sides of the equation.

−7f=12

Step 2: Divide both sides by -7.

−7f

−7

=

12

−7

f=

−12

7

Step-by-step explanation

sorry for the answer like this i couldnt find the fractions but the answer is f=-12/7 sorry :(

6 0

2 years ago