Maths Presentation

If every pupil scream individu in ally early(a) on a mobile phone, how many calls aim there be all told when there are 910 pupils? Ok. So if two heap rang severally some other wherefore it would olfactory modality give care this: =pupil 2 pupils=1 contacts =contact This shows that two wad provoke only basketball hoop each other once. If 3 people rang each other, then it would look like this: and so on and so forth... 3 pupils= 3 contacts 4 pupils= 6 contacts If I impute all the combinations in up to 6 in a epoch then it would look like this: 2 3 4 5 6>>>>>>>>>> no. status 1 3 6 10 15>>>>>>>> sequence 2 3 4 5 >>>>>>>>>>>difference 1 1 1 To find the nth term an2+bn+c II. 4a+2b+c=1 troika. 9a+3b+c=3 IV. 16a+4b+c=6 presently I am going to fray come on the c by taking away comparability II from troika: V.

(9a+3b+c=6) (4a+2b+c=1) = (5a+b=2) thusly I willing do the same for equation III and IV: VI. (16a+4b+c=6) (9a+3b+c=3) = 7a+b=3 Now to trifle out what a is, I will minus equation V from equation VI. VII. (7a+b=3) (5a+b=2) = 2a=1 a=0.5 upon decision out that a equals 0.5, I can change by reversal out that... (5x0.5)+b=2 2.5+b=2 ...b=-0.5 So now I will go vertebral towboat to equation II to work out what c is: 4x0.5+2x-0.5+c=1 2+ (-1)+c=1 C=0 So the formula is: 0.5n2+ (-0.5n)=y So question asks how many calls would there be if 910 students called each other once. Now I can work out what it is by replacing n for 910: 0.5n2+ (-0.5n)=n(n+1)2=910(910+1)2=414 505If you motivation to get a downright essay, order it on our website: Ordercustompaper.com

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