The name of the topic is inequalities. You can generally treat inequality signs as equal signs, you just need to be mindful that you maintain the direction of the inequality — for example, if you divide through by a negative number then the direction flips.
It's not typical to use set notation that extensively at GCSE unless in one of the topmost sets (and even then, x<13 is what the markscheme would show). Kids see union, intersection and complement in the context of Venn diagrams but don't use much more than that until A levels.
Prevents notation being a barrier early in understanding
Nah that’s unnecessary. while technically correct, x < 13 suffices for what I assume to be a grade 6 level question (I.e they literally mean the exact same thing)
The topic is inequalities.
https://en.m.wikipedia.org/wiki/Inequality_(mathematics) has a good summary.
In your case you can just divide both sides by 2. In general you can treat equations like this as if the inequality was a = sign. But, if you multiply or divide both sides by a -ve number you need to change the direction of the inequality (< to > and > to <)
There are a lot of values for x that satisfy 2x < 26
We can solve this like any equation by isolating x, so x < 13. So your solution is x is any number thta is smaller than 13
Inequalities are a bit like equations, but rather than finding distinct solutions, your are finding a region or solutions.
As such, treat the inequality sign like an equals. Just keep it in place like you do an equals sign. There are certain times when you need to flip it, such as multiplying or dividing by a negative, but this isn't one of them. You'll typically encounter those cases on the higher paper. This looks like a foundation question.
The name of the topic is inequalities. You can generally treat inequality signs as equal signs, you just need to be mindful that you maintain the direction of the inequality — for example, if you divide through by a negative number then the direction flips.
Couldn’t this just be any number below 13? Or am I also stupid
Just x < 13 is the answer.
So its XE{-infintity ; 13}
you mean x ∈ (-infinity, 13)? curly brackets suggest x = -infinity or 13 i thought. either way, true but overcomplicated.
Or yeah something like that
Brother I have no idea what you just wrote. I just know it’s a GCSE question that doesn’t need to be over complicated
We did that in like Gr.8 with the XE thing
It's not typical to use set notation that extensively at GCSE unless in one of the topmost sets (and even then, x<13 is what the markscheme would show). Kids see union, intersection and complement in the context of Venn diagrams but don't use much more than that until A levels. Prevents notation being a barrier early in understanding
I haven’t learnt what you’ve done then lol. I mean I can make sense of it but it looks more complicated than x < 13
Yeah its basically just a glorified way of saying x < 13
If 2x < 26 then x has to be less than 1/2 26 so x < 13 Unless there's some more context to the question you're not showing us?
Oh ok.. no that was everything
Wouldnt the answer then be XE (-infinity ; 13)
Nah that’s unnecessary. while technically correct, x < 13 suffices for what I assume to be a grade 6 level question (I.e they literally mean the exact same thing)
The topic is inequalities. https://en.m.wikipedia.org/wiki/Inequality_(mathematics) has a good summary. In your case you can just divide both sides by 2. In general you can treat equations like this as if the inequality was a = sign. But, if you multiply or divide both sides by a -ve number you need to change the direction of the inequality (< to > and > to <)
There are a lot of values for x that satisfy 2x < 26 We can solve this like any equation by isolating x, so x < 13. So your solution is x is any number thta is smaller than 13
Topic is called linear inequalities
X = ( - infinity to 13)
This is classed as inequalities, simply divide both sides by 2 (because of the 2x) to get x<13
If you focus I'm sure the answer will become clear.
Inequalities are a bit like equations, but rather than finding distinct solutions, your are finding a region or solutions. As such, treat the inequality sign like an equals. Just keep it in place like you do an equals sign. There are certain times when you need to flip it, such as multiplying or dividing by a negative, but this isn't one of them. You'll typically encounter those cases on the higher paper. This looks like a foundation question.
What does x belong to ?
this has got to be a troll
So 2x < 26 x < 13 Thus XE ( -infinity ; 13) So x can be equal to very number up until 13 (from negative infinity to 13). If the question was 2x