Đáp án:
Bạn tham khảo nhé!
Giải thích các bước giải:
${\rm e)}\,\dfrac{3x-7}{8}=\dfrac52\\\Rightarrow\dfrac{3x-7}{8}=\dfrac{20}{8}\\\Rightarrow 3x-7=20\\\Rightarrow 3x=27\\\Rightarrow x=9\\{\rm f)}\,x:0,2=0,8:x\\\Rightarrow x^2=0,2.0,8\\\Rightarrow x^2=\dfrac{4}{25}\\\Rightarrow x^2=\left(\pm\dfrac25\right)^{\large2}\\\Rightarrow x=\pm\dfrac25\\{\rm g)}\,\dfrac{x+11}{14-x}=\dfrac23\\\Rightarrow 3.(x+11)=2.(14-x)\\\Rightarrow 3x+33=28-2x\\\Rightarrow 5x+33=28\\\Rightarrow 5x=-5\\\Rightarrow x=-1$
