Cho \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqaMDevLHfij5gC1rhimfMBNvxyNvgaCLMB0XfBP1 % wA0n3x7btFETxB9ThxSvMz0HciYG3k2acxYL2zOrxkCrxz4r3EK1hE % 91ZnamXvP5wqSXMqHnxAJn0BKvguHDwzZbqefqvATv2CG4uz3bIuV1 % wyUbqedmvETj2BSbqefm0B1jxALjhiov2DaebbnrfifHhDYfgasaac % H8YjY-vipgYlh9vqqj-hEeeu0xXdbba9frFj0-OqFfea0dXdd9vqai % -hGuQ8kuc9pgc9q8qqaq-dir-f0-yqaiVgFr0xfr-xfr-xb9adbaqa % aeGaciGaaiaabeqaamaabaabaaGcbaaeaaaaaaaaa8qadaWdXbWdae % aapeWaaeWaa8aabaWdbiaaikdacaWG4bGaey4kaSIaaGOnaaGaayjk % aiaawMcaaiaabsgacaWG4baal8aabaWdbiaaicdaa8aabaWdbiaad2 % gaa0Gaey4kIipakiabg2da9iaaiEdaaaa!5DC2! \int\limits_0^m {\left( {2x + 6} \right){\rm{d}}x} = 7\). Tìm m
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Lời giải:
Báo sai\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqaM9-gbqvzybssUbxD0bctH52z1f2zLbWECLMB0X % fBP1wA0n3x7btFETxB9ThxSvMz0HciYG3k2acxYL2zOrxkCrxz4r3E % K1hE91ZnCXuzMrNCPDgA0fMCY92DGWfBLzgDUacxSvMz0Hci7ThE95 % 1EY0xFRydEGWLCPDgA0LciCjxANHgD891EW0Nx7jtF9CdxmvMz0jxA % NHgDHjNCVDhi7TxB951EY0xFRytB9CdxmvMz0jxANHgDHjNCVDhi7T % xB951EY0xFRytBTCtpWWftLzgDYL2zOrxyYj3B3bcxSvMz0TfiCjwz % NLMB7fgBPDMB91aiGyciT1tmGWfxG0aiMasB90YnGWfxG0axL5gz7f % gBPDMB9bcxYL2zOrNl9bWexLMBbXgBcf2CPn2qVrwzqf2zLnharuav % P1wzZbItLDhis9wBH5garmWu51MyVXgaruWqVvNCPvMCG4uz3bqee0 % evGueE0jxyaibaieYlNi-xH8yiVC0xbbL8F4rqqrFfpeea0xe9Lq-J % c9vqaqpepm0xbbG8FasPYRqj0-yi0dXdbba9pGe9xq-JbbG8A8frFv % e9Fve9Ff0dmeaabaqaciGacaGaaeqabaWaaeaaeaaakeaaqaaaaaaa % aaWdbmaapehapaqaa8qadaqadaWdaeaapeGaaGOmaiaadIhacqGHRa % WkcaaI2aaacaGLOaGaayzkaaGaaeizaiaadIhaaSWdaeaapeGaaGim % aaWdaeaapeGaamyBaaqdcqGHRiI8aOGaeyypa0JaaG4naiabgsDiBp % aaeiaapaqaa8qadaqadaWdaeaapeGaamiEa8aadaahaaWcbeqaa8qa % caaIYaaaaOGaey4kaSIaaGOnaiaadIhaaiaawIcacaGLPaaaaiaawI % a7a8aadaqhaaWcbaWdbiaaicdaa8aabaWdbiaaikdaaaGccqGH9aqp % caaI3aGaeyi1HSTaamyBa8aadaahaaWcbeqaa8qacaaIYaaaaOGaey % 4kaSIaaGOnaiaad2gacqGH9aqpcaaI3aGaeyi1HSTaamyBa8aadaah % aaWcbeqaa8qacaaIYaaaaOGaey4kaSIaaGOnaiaad2gacqGHsislca % aI3aGaeyypa0JaaGimaiabgsDiBpaadeaapaabaeqabaWdbiaad2ga % cqGH9aqpcaaIXaaapaqaa8qacaWGTbGaeyypa0JaeyOeI0IaaG4naa % aacaGLBbaaaaa!D59D! \int\limits_0^m {\left( {2x + 6} \right){\rm{d}}x} = 7 \Leftrightarrow \left. {\left( {{x^2} + 6x} \right)} \right|_0^2 = 7 \Leftrightarrow {m^2} + 6m = 7 \Leftrightarrow {m^2} + 6m - 7 = 0 \Leftrightarrow \left[ \begin{array}{l} m = 1\\ m = - 7 \end{array} \right.\)