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Find the value of x in the equation x^2 - 2x + 1 = 0

Factorise: X^2 means 2 brackets (x )(x )=0 factors of 1 = 1 (x 1)(x 1)=0 to get minus 2 you must do (-1) + (-1) so (x-1)(x-1)=0 therefore x-1=0 and x=1
LC
Answered by Louise C. • Maths tutor
4378 Views

Can lymphocytes have proteins that are complementary to host cell antigens?

You only kill off the ones that are reactive to host antigens (read: the ones that would attack your own cells!). So normal lymphocytic function isn't affected. Because of the nature of the immune system (yo...
SM
Answered by Scott M. • Biology tutor
3888 Views

Why is there no wave for atrial repolarisation in the electrocardiogram?

While atrial repolarisation exists, you actually can't see it in the ECG! I can draw you a diagram of a normal cardiac cycle: this is the P wave, that you'll know represents the DEpolarisation of the atria. ...
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7452 Views

What is more important, quoting philosophers or having my own opinions

IB philosophy is set out for you to become the philosopher. It is more important to have you own opinion on each topic, using philosophers ideas to back up your opinion rather than quoting them. It is less i...
TF
2650 Views

When should you use the passé simple instead of the imparfait?

The "passé simple" is most often used in literary and formal writing express a completed past action. E.g. Un jour, elle tomba malade. (one day, she fell ill) The "imparfait" on the other...
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Answered by Annabel V. • French tutor
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