Maths Olympiad Prep

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, 2020

Algebra Difficulty 1.1 Junior Find the answer Canada

For every real number xx, the expression (x+1)2x2(x+1)^2 - x^2 is equal to

2x+12x+1
2x12x-1
(2x+1)2(2x+1)^2
1-1
x+1x+1

A number or a short expression. Fractions can be typed as 3/2, and spacing doesn't matter.

Solution

Expanding and simplifying, (x+1)2x2=(x2+2x+1)x2=2x+1(x+1)^2 - x^2 = (x^2 + 2x + 1) - x^2 = 2x + 1.

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Source: CEMC, University of Waterloo, licensed CC-BY-NC-4.0. Statement reproduced verbatim; metadata (topic, difficulty) added by this project.