7th grade foundations (Eureka Math/EngageNY)
- Equation word problem: super yoga (1 of 2)
- Equation word problem: super yoga (2 of 2)
- One-step equations review
- Writing expressions with variables
- Inequality word problem: one variable
- Inequalities word problems
- Plotting an inequality example
- Plotting inequalities
This time we're creating a variable to represent a number, and then writing an inequality. We're building on our knowledge. Created by Sal Khan.
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- Why when the circle is closed does it include the number?(5 votes)
- When the circle is closed it means it includes the number. If you asking why, well i guess that's how its defined.(15 votes)
- Hello! We were given this math problem in class but my teacher said it's undefined. We were asked to put either a less than or greater than sign between x 2x
I put < sign because x is the same as 1x and 1x and is less than 2x. Am i wrong?(4 votes)
- My page does not load on the sections where I have to answer the questions. Every section marked by a star, I am having difficulty loading. Can you help me?(2 votes)
- How can you solve this inequality x is less than or equal to 100? Give an example.(3 votes)
- You don't really "solve" inequalities. Inequalities represent a set of allowed values. You can test a value and solve for whether it's true or not. So you could test for x equal to 7, and solving
x < 100for 7 gives
7 < 100, which is true. So 7 is included in the inequality for x.(3 votes)
The Karman line is the point at which the Earth's atmosphere ends and outer space begins. The Karman line is at 62 miles above sea level. And any distance from sea level at the Karman line or above is considered outer space. Set c equals 62 and use x to represent distance from sea level. Write an inequality in terms of x and c that represents the distances from sea level that are inside Earth's atmosphere. So we want to write an inequality in terms of x and c. And x is the distance above sea level, and c is the Karman line. And we want to think about things-- we want to think about distances that are inside Earth's atmosphere. So that's going to be anything that's below the Karman line. And so, let's see, I would write x is less than c, because they're telling us c is 62. Now, I want to make sure. So they say the Karman line is the point at which the Earth's atmosphere ends and outer space begins. So what if we're right at 62 miles? The Karman line is 62 miles above sea level, and any distance from sea level at the Karman line or above is considered outer space. OK. So if I'm at c or above, I'm in outer space. So only the things that are not, I'm sure, they're strictly below c. So I'm going to do a less than, not a less than or equal sign right over here. All right, got it right. Let's do another one. A black hole is a region of space where the pull of gravity is so strong that nothing can get back out once it has fallen inside. Let's use E to represent the largest distance from the center of the black hole that pulls objects inside. If x represents the distance of an object from the center of the black hole, write an inequality for safe distances from the center of the black hole in terms of x and E. So x is the distance from the center. e represents the largest distance from the center of the black hole that pulls objects inside. So if you're at E away or closer, you're going to be pulled inside. But we want to think about safe distances. So if you're further away than E, you should be cool. And it's strictly greater than because if you're at E, that's the largest distance that you would still be pulled inside. Very good.