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13 minutes ago, Ultrastu said:

7n+2 is 9 

Is not the same as

7n+2 =9 

What's the grid for .?

 

Your guess is as good as mine 

14 minutes ago, Ultrastu said:

7n+2 is 9 

Is not the same as

7n+2 =9 

What's the grid for .?

 

Thanks I'm just trying to get my head around it 👍

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2 hours ago, harrycatcat1 said:

Any ideas?

Screenshot_20210415-192955_WhatsApp.jpg

I didn't have a Scooby but I knew you didn't solve the equation normally. I asked a shooting champ I know who happens to be a maths genius (writes maths papers).

 

It’s reversing and balancing an equation to find an unknown. Start by taking 2 from both sides. The remember that 7n means 7 times n so divide both sides by 7 to get the value of 1 lot of n.

What you actually need to do is put n= 10 into the expression 7n + 2 and get 70 + 2 = 72

The sequence is 9, 16, 23....

 You replace the n with 1 to get the first term, 2 to get the second term etc

 

HTH because I understand what was said but am at a loss as to why it works like that. I need to retake maths. It had moved on since the 90s.

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I remember as a 14 year old boy being on the verge of tears in a 1-to-1 session with my maths teacher when he was trying to help me get my head around algebra.

"BUT YOU CAN'T ADD NUMBERS TOGETHER!!" I protested!  Took a while for the penny to drop but credit to my teacher for his patience, we got there in the end.

If in doubt, say the answer is 42 ;)

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51 minutes ago, dodgy dave said:

but what use is it

Education is not necessarily about learning useful information but training your mind in a way of thinking, so that it can be used in different applications. I do not use integration or differentiation in any aspect of my life, but I use the analytical and logical thought processes that were trained in pure mathematics daily. 

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72.  7n+2 is the nth term rule. 

The term to term rule is add 7 to the previous term.

If you wanted to know the 137th term in the sequence you could start from 9 and go up in 7 for 137 times or you can use the nth term rule

(7x137) + 2 = 961

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In near 42 years I've never needed algebra or the formula to work out the circumference of a circle or volume of a sphere or the stored energy of a rollacoaster ride at the top of a loop.  A few times, not many, I've had to count past 20. 

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6 hours ago, GingerCat said:

In near 42 years I've never needed algebra or the formula to work out the circumference of a circle or volume of a sphere or the stored energy of a rollacoaster ride at the top of a loop.  A few times, not many, I've had to count past 20. 

Ah!, but you are a copper

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In terms of 'when will I ever use this', I tend to explain that learning Mathematics helps develops different aspects of the brain: reasoning, logic, problem solving, acceptance of new ideas etc.

The maths subject content has hardly changed in the almost thirty years I've been teaching it.

I always tell pupils that they'll get a genuine 20th century education from me at no extra cost!

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20 hours ago, dodgy dave said:

but what use is it

It depends on context .

try this !

a= 20 , b =?  ,c =18

501 = 7a + 3b + 2c

what is b ?

The vast majority of you have tried this !

 

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35 minutes ago, GingerCat said:

Used to be a cnc machine operator with 2 18 feet band saws, a flat bed loader thingy and 20 head moulder. Still didn't need gcse math. 

I think I've got you there, did you never use trig?

Basic math and trig is about all I ever use.

19 hours ago, WalkedUp said:

Education is not necessarily about learning useful information but training your mind in a way of thinking, so that it can be used in different applications. I do not use integration or differentiation in any aspect of my life, but I use the analytical and logical thought processes that were trained in pure mathematics daily. 

Bang on, it's good to make the grey matter work, but I'm very glad my mrs is a lot smarter than me 😄

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