(4a+b)(3a+b)(2a－b)(a－b)
=(4a+b)(2a－b)(3a+b)(a－b)
=(8a^2－2ab－b^2)(6a^2－2ab－b^2)
(2ab+b^2)をMとする
(8a^2－M)(6a^2－M)
=48a^4－14a^2M+M^2
戻して
=48a^4－14a^2(2ab+b^2)+(2ab+b^2)^2
=48a^4－28a^3b－14a^2b^2+4a^2b^2+4ab^3+b^4
=48a^4－28a^3b－10a^2b^2+4ab^3+b^4
で、どうでしょう？
![中学3年2次方程式の問題です。
問題文の[1つだけ整数の解をもつとき]と[2つの異なる整数... - 1](https://d1e9oo257tadp1.cloudfront.net/uploads/qa_question_image/file/1808181/thumb_l_webp_17834198910490.webp?Expires=1783858585&Signature=u1a6WaEic4uWMMD5xT~QV-5db-fHfWAvj0tuvnsug~8GszjPE6tuTsKZqf19c3pq7mn4HtlkNhpn4T9KC7GgLjTvQO22yJEoX7pGl4eaTJsG5Q~2F74UHgPLe-hhuXuFrrKRvbog47~q88vPlWv7MOWnnvVfRQJ6zppcrie-LEIYdS1Qz8jeRpTNn69k8cbPpUb4PzPWE9-j~pZg7GsWK~H9zWcUq9ZvYjZ-FeWccXFQZPYTh5FQ7RB5Xg-kYAB4kFq6g5sp6duDfzcwz5QVaEBLdEtGLgsBwLMyE0p1ihCt2kNPRP3vcbifcNvUWQ-DNhfwIgEx7d7vsihdfudgTA__&Key-Pair-Id=K2W722D70GJS8W&Expires=1783858585&Signature=nteKxqx1hEsDRtUv7mjOfu5KYI4XcALDCYS0SY3Ns65vmojHB2WyEQNWDM~A-a5MYerp~TbmbOqHWqn9VzIg4JG-llZV7YaZu1gGymfpLayScxkOzAPdtOk-niDk4q6tkhfArerAZoAnzLv7Vl7LBpLTgllfCmoott21DCHBABfAZHf5w5ndarm77BXzsr5jOowZGKSWXUk2hd39601TRNR02MAIf10SlDWyVLXIIJsvmLPyMzAG6Hj8UBB53VkAG10BZbQCuCOqFDFZhuA7HrWp40uZCrhYOulcmBeSifV01Do8bQzAR-uR8al2pdBUrAmcg~9YP8QnwAp7ecEVcw__&Key-Pair-Id=K2W722D70GJS8W)
