SOLUTION: factorise the following; 1)x^2+2x-3 2)x^2-x+6 3)x^3+27

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Question 983542: factorise the following;
1)x^2+2x-3
2)x^2-x+6
3)x^3+27
Answer by josgarithmetic(39630) About Me  (Show Source):
You can put this solution on YOUR website!
#1 and #2, just try the different combinations.
x%5E2%2Brx%2Bt=%28x%2Ba%29%28x%2Bb%29=x%5E2%2Bax%2Bbx%2Bab=x%5E2%2B%28a%2Bb%29x%2Bab
You want ab=t and a%2Bb=r.
Make all the combinations of a and b that you can, and test each of them.

#3 is a special product.
a%5E3%2Bb%5E3=%28a%2Bb%29%28a%5E2-ab%2Bb%5E2%29;
Your example has x=a and 3=b.