A number or a short expression. Spacing and $ signs are ignored.
Solution
When x=2, we have (x+2−x)(2−x−2)=(2+2−2)(2−2−2)=(2)(−2)=−4. Alternatively, we could simplify (x+2−x)(2−x−2) to obtain (2)(−x) or −2x and then substitute x=2 to obtain a result of −2(2) or -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.