Trong không gian với hệ trục tọa độ Oxyz, mặt phẳng \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaeWaaeaaca % WGqbaacaGLOaGaayzkaaGaaiOoaiaadggacaWG4bGaey4kaSIaamOy % aiaadMhacqGHRaWkcaWGJbGaamOEaiabgkHiTiaaiMdacqGH9aqpca % aIWaaaaa!43F2! \left( P \right):ax + by + cz - 9 = 0\) chứa hai điểm A(3;2;1) ; B(-3;5;2) và vuông góc với mặt phẳng \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaeWaaeaaca % WGrbaacaGLOaGaayzkaaGaaiOoaiaaiodacaWG4bGaey4kaSIaamyE % aiabgUcaRiaadQhacqGHRaWkcaaI0aGaeyypa0JaaGimaaaa!41EB! \left( Q \right):3x + y + z + 4 = 0\). Tính tổng S = a+b+c.
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Lời giải:
Báo sai\(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaiqaaqaabe % qaaiaaiodacaWGHbGaey4kaSIaaGOmaiaadkgacqGHRaWkcaWG4bGa % eyOeI0IaaGyoaiabg2da9iaaicdaaeaacqGHsislcaaIZaGaamyyai % abgUcaRiaaiwdacaWGIbGaey4kaSIaaGOmaiaadogacqGHsislcaaI % 5aGaeyypa0JaaGimaaqaaiaaiodacaWGHbGaey4kaSIaamOyaiabgU % caRiaadogacqGH9aqpcaaIWaaaaiaawUhaaiabgsDiBpaaceaaeaqa % beaacaWGHbGaeyypa0JaaGOmaaqaaiaadkgacqGH9aqpcaaI5aaaba % Gaam4yaiabg2da9iabgkHiTiaaigdacaaI1aaaaiaawUhaaiabgkDi % ElaadggacqGHRaWkcaWGIbGaey4kaSIaam4yaiabg2da9iabgkHiTi % aaisdaaaa!6942! \left\{ \begin{array}{l} 3a + 2b + x - 9 = 0\\ - 3a + 5b + 2c - 9 = 0\\ 3a + b + c = 0 \end{array} \right. \Leftrightarrow \left\{ \begin{array}{l} a = 2\\ b = 9\\ c = - 15 \end{array} \right. \Rightarrow a + b + c = - 4\)
Đề thi thử tốt nghiệp THPT QG môn Toán năm 2020
Tuyển chọn số 5