Giúp mình bài 6A với ạ😅
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
8: \(\left(-4\right)\cdot3\cdot\left(-125\right)\cdot25\cdot\left(-8\right)\)
\(=-4\cdot25\cdot125\cdot8\cdot3\)
\(=-3\cdot100\cdot1000=-300000\)
9: \(-25\cdot8\cdot\left(-125\right)\cdot3\cdot\left(-4\right)\)
\(=-25\cdot8\cdot125\cdot4\cdot3\)
\(=-3\cdot25\cdot4\cdot8\cdot125\)
\(=-3\cdot100\cdot1000=-300000\)
10: \(147\cdot333+233\cdot\left(-147\right)\)
\(=147\left(333-233\right)\)
\(=147\cdot100=14700\)
11: \(-115\cdot27+33\cdot\left(-115\right)\)
\(=\left(-115\right)\left(27+33\right)\)
\(=-115\cdot60=-6900\)
12: \(45\cdot\left(-24\right)+\left(-10\right)\cdot\left(-12\right)\)
\(=-45\cdot2\cdot12+10\cdot12\)
\(=-24\left(45-5\right)\)
\(=-24\cdot40=-960\)
13: \(-\left(-4\right)^2\cdot3^2\cdot\left(-5\right)^3\)
\(=-16\cdot9\cdot\left(-125\right)\)
\(=16\cdot9\cdot125=9\cdot2\cdot8\cdot125=18\cdot1000=18000\)
14: \(2-4+6-8+...-48+50\)
\(=\left(2-4\right)+\left(6-8\right)+...+\left(46-48\right)+50\)
\(=\left(-2\right)+\left(-2\right)+...+\left(-2\right)+50\)
\(=50-2\cdot24=2\)
a) \(\sqrt{-\dfrac{2t}{3}}.\sqrt{-\dfrac{3t}{8}}=\sqrt{-\dfrac{2t}{3}.\left(-\dfrac{3t}{8}\right)}=\sqrt{\dfrac{1}{4}t^2}=\left|\dfrac{1}{2}t\right|=-\dfrac{1}{2}t\left(t< 0\right)\)
b) \(\sqrt{\dfrac{2a^3}{b}}:\sqrt{\dfrac{ab^3}{8}}=\sqrt{\dfrac{2a^3}{b}:\dfrac{ab^3}{8}}=\sqrt{\dfrac{2a^3}{b}.\dfrac{8}{ab^3}}=\sqrt{16\dfrac{a^2}{b^4}}\)
\(=\left|4\dfrac{a}{b^2}\right|=-\dfrac{4a}{b^2}\left(a< 0\right)\)
c) \(\sqrt{x-\sqrt{x^2-1}}.\sqrt{x+\sqrt{x^2-1}}=\sqrt{\left(x-\sqrt{x^2-1}\right)\left(x+\sqrt{x^2-1}\right)}\)
\(=\sqrt{x^2-\left(x^2-1\right)}=\sqrt{1}=1\)