Question

Помогите, пожалуйста, решить

Answer 1

$1)\\\dfrac{2}{15} +\dfrac{7}{12}=\dfrac{2\cdot4+7\cdot5}{60}=\dfrac{8+35}{60}=\dfrac{43}{60}\\\\\\\dfrac{43}{60}\cdot\dfrac{30}{43}=\dfrac{1}{2} \\\\\\\Big(2:2\dfrac{1}{2} \Big)\cdot\dfrac{5}{32}=2\cdot\dfrac{2}{5}\cdot\dfrac{5}{32}=\dfrac{1}{8}\\\\\\\dfrac{1}{2} -\dfrac{1}{8} =\dfrac{4-1}{8}=\dfrac{3}{8} =\boxed{0,375}$

$2) \ 2,5x-1,7=0,4x-0,5x-1,3x+1,4+3,4x\\\\0,4x-0,5x-1,3x+3,4x-2,5x=-1,4-1,7\\\\-0,5x=-3,1\\\\\boxed{x=6,2}\\\\\\\\2|x-1|+1=9\\\\2|x-1|=8\\\\|x-1|=4\\\\\left[\begin{array}{ccc}x-1=4\\x-1=-4\end{array}\right\\\\\\\left[\begin{array}{ccc}x_{1} =5\\x_{2} =-3\end{array}\right\\\\\\Otvet:\boxed{5 \ ; \ -3}$