Câu hỏi của Quyết Nguyễn

Question

hộ mik cột b đc ko

Nguyễn Lê Phước Thịnh · Accepted Answer

b: (1/2)^x=1/32=>(1/2)^x=(1/2)^5=>x=5b: (7/5)^x=343/125=>(7/5)^x=(7/5)^3=>x=3b: (-3/2)^x=9/4=>(-3/2)^x=(-3/2)^2=>x=2b: (-2/3)^x=-8/27=>(-2/3)^x=(-2/3)^3=>x=3b: (3/5)^x+98/125=1=>(3/5)^x=27/125=>(3/5)^x=(3/5)^3=>x=3Câu trả lời: b: (1/2)^x=1/32=>(1/2)^x=(1/2)^5=>x=5b: (7/5)^x=343/125=>(7/5)^x=(7/5)^3=>x=3b: (-3/2)^x=9/4=>(-3/2)^x=(-3/2)^2=>x=2b: (-2/3)^x=-8/27=>(-2/3)^x=(-2/3)^3=>x=3b: (3/5)^x+98/125=1=>(3/5)^x=27/125=>(3/5)^x=(3/5)^3=>x=3

HT.Phong (9A5) · Answer

b1) $\left(\dfrac{1}{2}\right)^x=\dfrac{1}{32}$$\Rightarrow\left(\dfrac{1}{2}\right)^x=\left(\dfrac{1}{2}\right)^5$$\Rightarrow x=5$b2) $\dfrac{343}{125}=\left(\dfrac{7}{5}\right)^x$$\Rightarrow\left(\dfrac{7}{5}\right)^3=\left(\dfrac{7}{5}\right)^x$$\Rightarrow x=3$b3) $\left(-\dfrac{3}{2}\right)^x=\dfrac{9}{4}$$\Rightarrow\left(-\dfrac{3}{2}\right)^x=\left(-\dfrac{3}{2}\right)^2$$\Rightarrow x=2$b4) $\left(-\dfrac{2}{3}\right)^x=-\dfrac{8}{27}$$\Rightarrow\left(-\dfrac{2}{3}\right)^x=\left(-\dfrac{2}{3}\right)^3$$\Rightarrow x=3$b5) $\left(\dfrac{3}{5}\right)^x+\dfrac{98}{125}=1$$\Rightarrow\left(\dfrac{3}{5}\right)^x=1-\dfrac{98}{125}$$\Rightarrow\left(\dfrac{3}{5}\right)^x=\dfrac{27}{125}$$\Rightarrow\left(\dfrac{3}{5}\right)^x=\left(\dfrac{3}{5}\right)^3$$\Rightarrow x=3$Câu trả lời: b1) $\left(\dfrac{1}{2}\right)^x=\dfrac{1}{32}$$\Rightarrow\left(\dfrac{1}{2}\right)^x=\left(\dfrac{1}{2}\right)^5$$\Rightarrow x=5$b2) $\dfrac{343}{125}=\left(\dfrac{7}{5}\right)^x$$\Rightarrow\left(\dfrac{7}{5}\right)^3=\left(\dfrac{7}{5}\right)^x$$\Rightarrow x=3$b3) $\left(-\dfrac{3}{2}\right)^x=\dfrac{9}{4}$$\Rightarrow\left(-\dfrac{3}{2}\right)^x=\left(-\dfrac{3}{2}\right)^2$$\Rightarrow x=2$b4) $\left(-\dfrac{2}{3}\right)^x=-\dfrac{8}{27}$$\Rightarrow\left(-\dfrac{2}{3}\right)^x=\left(-\dfrac{2}{3}\right)^3$$\Rightarrow x=3$b5) $\left(\dfrac{3}{5}\right)^x+\dfrac{98}{125}=1$$\Rightarrow\left(\dfrac{3}{5}\right)^x=1-\dfrac{98}{125}$$\Rightarrow\left(\dfrac{3}{5}\right)^x=\dfrac{27}{125}$$\Rightarrow\left(\dfrac{3}{5}\right)^x=\left(\dfrac{3}{5}\right)^3$$\Rightarrow x=3$

Kiều Vũ Linh · Answer

a) $\left(x+\dfrac{1}{2}\right)^2=\dfrac{1}{16}$$x+\dfrac{1}{2}=\dfrac{1}{4}$ hoặc $x+\dfrac{1}{2}=-\dfrac{1}{4}$*) $x+\dfrac{1}{2}=\dfrac{1}{4}$$x=\dfrac{1}{4}-\dfrac{1}{2}$$x=-\dfrac{1}{2}$*) $x+\dfrac{1}{2}=-\dfrac{1}{4}$$x=-\dfrac{1}{4}-\dfrac{1}{2}$$x=-\dfrac{3}{4}$Vậy $x=-\dfrac{3}{4};x=-\dfrac{1}{2}$----------------------------------------a) $\left(\dfrac{3}{4}-7x\right)^2=\dfrac{1}{4}$$\dfrac{3}{4}-7x=\dfrac{1}{2}$ hoặc $\dfrac{3}{4}-7x=-\dfrac{1}{2}$*) $\dfrac{3}{4}-7x=\dfrac{1}{2}$$7x=\dfrac{3}{4}-\dfrac{1}{2}$$7x=\dfrac{1}{4}$$x=\dfrac{1}{4}:7$$x=\dfrac{1}{28}$*) $\dfrac{3}{4}-7x=-\dfrac{1}{2}$$7x=\dfrac{3}{4}+\dfrac{1}{2}$$7x=\dfrac{5}{4}$$x=\dfrac{5}{4}:7$$x=\dfrac{5}{28}$Vậy $x=\dfrac{1}{28};x=\dfrac{5}{28}$----------------------------------------a) $\left(x-\dfrac{5}{6}\right)^2=\dfrac{1}{36}$$x-\dfrac{5}{6}=\dfrac{1}{6}$ hoặc $x-\dfrac{5}{6}=-\dfrac{1}{6}$*) $x-\dfrac{5}{6}=\dfrac{1}{6}$$x=\dfrac{1}{6}+\dfrac{5}{6}$$x=1$*) $x-\dfrac{5}{6}=-\dfrac{1}{6}$$x=-\dfrac{1}{6}+\dfrac{5}{6}$$x=\dfrac{2}{3}$Vậy $x=\dfrac{2}{3};x=1$----------------------------------------a) $\left(1-\dfrac{2}{3}x\right)^2=\dfrac{4}{9}$$1-\dfrac{2}{3}x=\dfrac{2}{3}$ hoặc $1-\dfrac{2}{3}x=-\dfrac{2}{3}$*) $1-\dfrac{2}{3}x=\dfrac{2}{3}$$\dfrac{2}{3}x=1-\dfrac{2}{3}$$\dfrac{2}{3}x=\dfrac{1}{3}$$x=\dfrac{1}{3}:\dfrac{2}{3}$$x=\dfrac{1}{2}$*) $1-\dfrac{2}{3}x=-\dfrac{2}{3}$$\dfrac{2}{3}x=1+\dfrac{2}{3}$$\dfrac{2}{3}x=\dfrac{5}{3}$$x=\dfrac{5}{3}:\dfrac{2}{3}$$x=\dfrac{5}{2}$Vậy $x=\dfrac{1}{2};x=\dfrac{5}{2}$----------------------------------------*) $\left(\dfrac{2}{3}-x\right)^2=1:\dfrac{4}{9}$$\left(\dfrac{2}{3}-x\right)^2=\dfrac{9}{4}$$\dfrac{2}{3}-x=\dfrac{3}{2}$ hoặc $\dfrac{2}{3}-x=-\dfrac{3}{2}$*) $\dfrac{2}{3}-x=\dfrac{3}{2}$$x=\dfrac{2}{3}-\dfrac{3}{2}$$x=-\dfrac{5}{6}$*) $\dfrac{2}{3}-x=-\dfrac{3}{2}$$x=\dfrac{2}{3}+\dfrac{3}{2}$$x=\dfrac{13}{6}$Vậy $x=-\dfrac{5}{6};x=\dfrac{13}{6}$Câu trả lời: a) $\left(x+\dfrac{1}{2}\right)^2=\dfrac{1}{16}$$x+\dfrac{1}{2}=\dfrac{1}{4}$ hoặc $x+\dfrac{1}{2}=-\dfrac{1}{4}$*) $x+\dfrac{1}{2}=\dfrac{1}{4}$$x=\dfrac{1}{4}-\dfrac{1}{2}$$x=-\dfrac{1}{2}$*) $x+\dfrac{1}{2}=-\dfrac{1}{4}$$x=-\dfrac{1}{4}-\dfrac{1}{2}$$x=-\dfrac{3}{4}$Vậy $x=-\dfrac{3}{4};x=-\dfrac{1}{2}$----------------------------------------a) $\left(\dfrac{3}{4}-7x\right)^2=\dfrac{1}{4}$$\dfrac{3}{4}-7x=\dfrac{1}{2}$ hoặc $\dfrac{3}{4}-7x=-\dfrac{1}{2}$*) $\dfrac{3}{4}-7x=\dfrac{1}{2}$$7x=\dfrac{3}{4}-\dfrac{1}{2}$$7x=\dfrac{1}{4}$$x=\dfrac{1}{4}:7$$x=\dfrac{1}{28}$*) $\dfrac{3}{4}-7x=-\dfrac{1}{2}$$7x=\dfrac{3}{4}+\dfrac{1}{2}$$7x=\dfrac{5}{4}$$x=\dfrac{5}{4}:7$$x=\dfrac{5}{28}$Vậy $x=\dfrac{1}{28};x=\dfrac{5}{28}$----------------------------------------a) $\left(x-\dfrac{5}{6}\right)^2=\dfrac{1}{36}$$x-\dfrac{5}{6}=\dfrac{1}{6}$ hoặc $x-\dfrac{5}{6}=-\dfrac{1}{6}$*) $x-\dfrac{5}{6}=\dfrac{1}{6}$$x=\dfrac{1}{6}+\dfrac{5}{6}$$x=1$*) $x-\dfrac{5}{6}=-\dfrac{1}{6}$$x=-\dfrac{1}{6}+\dfrac{5}{6}$$x=\dfrac{2}{3}$Vậy $x=\dfrac{2}{3};x=1$----------------------------------------a) $\left(1-\dfrac{2}{3}x\right)^2=\dfrac{4}{9}$$1-\dfrac{2}{3}x=\dfrac{2}{3}$ hoặc $1-\dfrac{2}{3}x=-\dfrac{2}{3}$*) $1-\dfrac{2}{3}x=\dfrac{2}{3}$$\dfrac{2}{3}x=1-\dfrac{2}{3}$$\dfrac{2}{3}x=\dfrac{1}{3}$$x=\dfrac{1}{3}:\dfrac{2}{3}$$x=\dfrac{1}{2}$*) $1-\dfrac{2}{3}x=-\dfrac{2}{3}$$\dfrac{2}{3}x=1+\dfrac{2}{3}$$\dfrac{2}{3}x=\dfrac{5}{3}$$x=\dfrac{5}{3}:\dfrac{2}{3}$$x=\dfrac{5}{2}$Vậy $x=\dfrac{1}{2};x=\dfrac{5}{2}$----------------------------------------*) $\left(\dfrac{2}{3}-x\right)^2=1:\dfrac{4}{9}$$\left(\dfrac{2}{3}-x\right)^2=\dfrac{9}{4}$$\dfrac{2}{3}-x=\dfrac{3}{2}$ hoặc $\dfrac{2}{3}-x=-\dfrac{3}{2}$*) $\dfrac{2}{3}-x=\dfrac{3}{2}$$x=\dfrac{2}{3}-\dfrac{3}{2}$$x=-\dfrac{5}{6}$*) $\dfrac{2}{3}-x=-\dfrac{3}{2}$$x=\dfrac{2}{3}+\dfrac{3}{2}$$x=\dfrac{13}{6}$Vậy $x=-\dfrac{5}{6};x=\dfrac{13}{6}$

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