Câu hỏi của Trần Nguyễn Hoài Thư

Question

Tìm x, biết rằng :a) x : ( -$\frac{1}{3}$ )3 = -$\frac{1}{3}$b) ( $\frac{4}{5}$ )5 . x = ( $\frac{4}{5}$ )7c) ( x + $\frac{1}{2}$ )2 = $\frac{1}{16}$d) ( 3x + 1 )3 = -27Các bạn giúp mình v...

Công Chúa Hoa Hồng · Accepted Answer

a) x : $\left(-\frac{1}{3}\right)^3=-\frac{1}{3}$$x:\frac{-1}{27}=\frac{-1}{3}$$x=\frac{-1}{3}.\frac{-1}{27}$$x=\frac{1}{81}$Vậy $x=\frac{1}{81}$Câu trả lời: a) x : $\left(-\frac{1}{3}\right)^3=-\frac{1}{3}$$x:\frac{-1}{27}=\frac{-1}{3}$$x=\frac{-1}{3}.\frac{-1}{27}$$x=\frac{1}{81}$Vậy $x=\frac{1}{81}$

Trần Việt Linh · Answer

a) $x:\left(-\frac{1}{3}\right)^3=-\frac{1}{3}$$\Leftrightarrow x=\left(-\frac{1}{3}\right)\cdot\left(-\frac{1}{3}\right)^3$$\Leftrightarrow x=\left(-\frac{1}{3}\right)^4$$\Leftrightarrow x=\frac{1}{81}$b)$\left(\frac{4}{5}\right)^5\cdot x=\left(\frac{4}{5}\right)^7$$\Leftrightarrow x=\left(\frac{4}{5}\right)^7:\left(\frac{4}{5}\right)^5=\left(\frac{4}{5}\right)^2=\frac{16}{25}$c)$\left(x+\frac{1}{2}\right)^2=\frac{1}{16}$$\Leftrightarrow x+\frac{1}{2}=\frac{1}{4}$$\Leftrightarrow x=-\frac{1}{4}$d)$\left(3x+1\right)^3=-27$$\Leftrightarrow3x+1=-3$$\Leftrightarrow3x=-4$$\Leftrightarrow x=-\frac{4}{3}$Câu trả lời: a) $x:\left(-\frac{1}{3}\right)^3=-\frac{1}{3}$$\Leftrightarrow x=\left(-\frac{1}{3}\right)\cdot\left(-\frac{1}{3}\right)^3$$\Leftrightarrow x=\left(-\frac{1}{3}\right)^4$$\Leftrightarrow x=\frac{1}{81}$b)$\left(\frac{4}{5}\right)^5\cdot x=\left(\frac{4}{5}\right)^7$$\Leftrightarrow x=\left(\frac{4}{5}\right)^7:\left(\frac{4}{5}\right)^5=\left(\frac{4}{5}\right)^2=\frac{16}{25}$c)$\left(x+\frac{1}{2}\right)^2=\frac{1}{16}$$\Leftrightarrow x+\frac{1}{2}=\frac{1}{4}$$\Leftrightarrow x=-\frac{1}{4}$d)$\left(3x+1\right)^3=-27$$\Leftrightarrow3x+1=-3$$\Leftrightarrow3x=-4$$\Leftrightarrow x=-\frac{4}{3}$

Võ Đông Anh Tuấn · Answer

a ) $x:\left(-\frac{1}{3}\right)^3=-\frac{1}{3}$$x=-\frac{1}{3}.\left(-\frac{1}{3}\right)^3$$x=\left(-\frac{1}{3}\right)^{3+1}$$x=\left(-\frac{1}{3}\right)^4$$x=\frac{1}{81}$b ) $\left(\frac{4}{5}\right)^5.x=\left(\frac{4}{5}\right)^7$$x=\left(\frac{4}{5}\right)^7:\left(\frac{4}{5}\right)^5$$x=\left(\frac{4}{5}\right)^{7-5}$$x=\left(\frac{4}{5}\right)^2$$x=\frac{16}{25}$c ) $\left(x+\frac{1}{2}\right)^2=\frac{1}{16}$$\left(x+\frac{1}{2}\right)=\sqrt{\frac{1}{16}}$$\left(x+\frac{1}{2}\right)=\frac{1}{4}$$x=-\frac{1}{4}$d ) $\left(3x+1\right)^3=-27$$\left(3x+1\right)=-\sqrt[3]{27}$$\left(3x+1\right)=-3$$3x=-2$$x=-\frac{2}{3}$Câu trả lời: a ) $x:\left(-\frac{1}{3}\right)^3=-\frac{1}{3}$$x=-\frac{1}{3}.\left(-\frac{1}{3}\right)^3$$x=\left(-\frac{1}{3}\right)^{3+1}$$x=\left(-\frac{1}{3}\right)^4$$x=\frac{1}{81}$b ) $\left(\frac{4}{5}\right)^5.x=\left(\frac{4}{5}\right)^7$$x=\left(\frac{4}{5}\right)^7:\left(\frac{4}{5}\right)^5$$x=\left(\frac{4}{5}\right)^{7-5}$$x=\left(\frac{4}{5}\right)^2$$x=\frac{16}{25}$c ) $\left(x+\frac{1}{2}\right)^2=\frac{1}{16}$$\left(x+\frac{1}{2}\right)=\sqrt{\frac{1}{16}}$$\left(x+\frac{1}{2}\right)=\frac{1}{4}$$x=-\frac{1}{4}$d ) $\left(3x+1\right)^3=-27$$\left(3x+1\right)=-\sqrt[3]{27}$$\left(3x+1\right)=-3$$3x=-2$$x=-\frac{2}{3}$

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