Вычислите: (234+215)⋅18\left (2\frac34+2\frac15 \right )\cdot18(243+251)⋅18▸Ответ89,1▸Решение(234+215)⋅18=\left (2\frac34+2\frac15 \right )\cdot18=(243+251)⋅18=(114+115)⋅18=\left (\frac{11}{4}+\frac{11}5 \right )\cdot18=(411+511)⋅18=(11⋅5+11⋅420)⋅18=\left(\frac{11\cdot5+11\cdot4}{20} \right)\cdot 18=(2011⋅5+11⋅4)⋅18=(55+4420)⋅18=9920⋅18=\left(\frac{55+44}{20}\right)\cdot18=\frac{99}{20}\cdot18=(2055+44)⋅18=2099⋅18=99⋅910=89110=89,1\frac{99\cdot 9}{10}=\frac{891}{10}=89,11099⋅9=10891=89,1