Question

Найдите значение выражения (с решением): 1) 3 4/5+3+(-11/10) 2) 3 3/4+1/5*1,25 3) 1——1+1/4 4)6,5: 1,3*22 5)(1,2+2,3)*5,6 6) 1/5*4,5- 7) 52,29: (8 41/70-2/7) выражение 5х-10+2х+20-10х-10 и найдите его значение при х=-1,3

Answer 1

$1)3\tt\displaystyle\frac{4}{5}+3+(-\frac{11}{10})=6\frac{4}{5}-\frac{11}{10}=\frac{34}{5}-\frac{11}{10}=\frac{68}{10}-\frac{11}{10}=\frac{57}{10}=5\frac{7}{10}=5,7$

$2)3\tt\displaystyle\frac{3}{4}+\frac{1}{5}*1,25=3\frac{3}{4}+\frac{1}{5}*1\frac{25}{100}=3\frac{3}{4}+\frac{1}{5}*1\frac{1}{4}=3\frac{3}{4}+\frac{1}{5}*\frac{5}{4}=3\frac{3}{4}+\frac{1}{4}=4$

$3)\tt\displaystyle\frac{1}{1+\frac{1}{4} }=\frac{1}{\frac{5}{4} }=1*\frac{4}{5}=\frac{4}{5}=0,8$

$4)6,5:1,3*22=5*22=110$

$5)(1,2+2,3)*5,6=3,5*5,6=19,6$

Не дописано условие:

$6)\tt\displaystyle\frac{1}{5}*4,5-1=\frac{1}{5}*4\frac{5}{10}-1=\frac{1}{5}*4\frac{1}{2}-1=\frac{1}{5}*\frac{9}{2}-1=\frac{9}{10}-1=\frac{9}{10}-\frac{10}{10}=-\frac{1}{10}$

$7)52,29:(8\tt\displaystyle\frac{41}{70}-\frac{2}{7})=52,29:(8\frac{41}{70}-\frac{20}{70})=52,29:8\frac{21}{70}=52,29:8\frac{3}{10}=52,29:8,3=6,3$

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5х - 10 + 2х + 20 - 10 х - 10 = - 3х

при х = - 1,3:

- 3х = (- 3) * (- 1,3) = 3,9