Maths Olympiad Prep

Library / /15 of 173

Algebra Difficulty 1.9 Junior Find the answer

What is the value of (3x+2y)(3x2y)(3x + 2y) - (3x - 2y) when x=2x = -2 and y=1y = -1?

A number or a short expression. Spacing and $ signs are ignored.

Solution

The expression (3x+2y)(3x2y)(3x + 2y) - (3x - 2y) is equal to 3x+2y3x+2y3x + 2y - 3x + 2y which equals 4y4y. When x=2x = -2 and y=1y = -1, this equals 4(1)4(-1) or 4-4.

Want a route through all this instead of an archive? The track puts 2,000 problems in a working order, from AMC 10 level to the IMO shortlist.

Source: Omni-MATH, licensed Apache-2.0. Statement and solution reproduced as published; topic and difficulty added by this site.