Maths Olympiad Prep

Library / /23 of 173

Algebra Difficulty 2.0 Junior Find the answer

The product of the roots of the equation (x4)(x2)+(x2)(x6)=0(x-4)(x-2)+(x-2)(x-6)=0 is

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

Solution

Since the two terms have a common factor, then we factor and obtain (x2)((x4)+(x6))=0(x-2)((x-4)+(x-6))=0. This gives (x2)(2x10)=0(x-2)(2x-10)=0. Therefore, x2=0x-2=0 (which gives x=2x=2) or 2x10=02x-10=0 (which gives x=5x=5). Therefore, the two roots of the equation are x=2x=2 and x=5x=5. Their product is 10.

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.