Question

геометрия 5 класс
найдите Х​

Answer 1

 

а)

$\displaystyle\bf\\x=14~cm~8~mm-8~cm~9~mm\\x=148~mm-89~mm=59~mm=\boxed{\bf5~cm~9~mm}$

б)

$\displaystyle\bf\\x=6~cm~7mm+14~cm~8~mm\\x=67~mm+148~mm=215~=\boxed{\bf21~cm~5~mm}$

в)

$\displaystyle\bf\\\Big(\frac{2}{3}+1\Big)x=125~mm\\\\\frac{1\times3+2}{3}x=125~mm\\\\\frac{5}{3}x=125~mm\\\\x=125:\frac{5}{3}\\\\x=125\times\frac{3}{5}=25\times5=75~mm=\boxed{\bf7~cm~5~mm}$

г)

$\displaystyle\bf\\x-\frac{1}{3}x=11~cm~2~mm\\\\\frac{2}{3}x=112~mm\\\\x=112:\frac{2}{3}\\\\x=112\times\frac{3}{2}=56\times3=168~mm=\boxed{\bf16~cm~8~mm}$

 

 

Answer 2

$\it x=148-89=59mm=5cm+9mm\\ \\ \\ x=67+148=215mm=21cm+5mm$

$\dfrac{2}{3}x+x=125|_{\cdot3} \Rightarrow 2x+3x=3\cdot125 \Rightarrow 5x=375|_{:5}\Rightarrow x=75mm=7cm5mm$