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1. 脱式计算。（能简算的要简算）
$(3618÷18 - 147)×27$
$(7.5 + 2.5×4.6)÷0.25$
$84÷[(\dfrac{5}{6}-\dfrac{3}{4})×4+\dfrac{3}{5}]$
$25×49×4$
$6.7 + 3.9 + 4.3 + 6.1$
$2.7×4.8 + 2.7×5.2$
$\dfrac{3}{8}÷[8×(\dfrac{3}{4}+\dfrac{1}{4})×\dfrac{1}{8}]$
$\dfrac{2004}{2005}×2004$
$\dfrac{6}{5}÷[(\dfrac{3}{4}-\dfrac{2}{3})÷\dfrac{5}{6}]$
$\dfrac{5}{18}×18 - 5×\dfrac{4}{7}$
$(3618÷18 - 147)×27$
$(7.5 + 2.5×4.6)÷0.25$
$84÷[(\dfrac{5}{6}-\dfrac{3}{4})×4+\dfrac{3}{5}]$
$25×49×4$
$6.7 + 3.9 + 4.3 + 6.1$
$2.7×4.8 + 2.7×5.2$
$\dfrac{3}{8}÷[8×(\dfrac{3}{4}+\dfrac{1}{4})×\dfrac{1}{8}]$
$\dfrac{2004}{2005}×2004$
$\dfrac{6}{5}÷[(\dfrac{3}{4}-\dfrac{2}{3})÷\dfrac{5}{6}]$
$\dfrac{5}{18}×18 - 5×\dfrac{4}{7}$
答案
(3618÷18 - 147)×27
=(201 - 147)×27
=54×27
=1458
(7.5 + 2.5×4.6)÷0.25
=(7.5 + 11.5)÷0.25
=19÷0.25
=76
84÷[($\dfrac{5}{6}$-$\dfrac{3}{4}$)×4+$\dfrac{3}{5}$]
=84÷[($\dfrac{10}{12}$-$\dfrac{9}{12}$)×4+$\dfrac{3}{5}$]
=84÷[$\dfrac{1}{12}$×4+$\dfrac{3}{5}$]
=84÷[$\dfrac{1}{3}$+$\dfrac{3}{5}$]
=84÷[$\dfrac{5}{15}$+$\dfrac{9}{15}$]
=84÷$\dfrac{14}{15}$
=84×$\dfrac{15}{14}$
=90
25×49×4
=25×4×49
=100×49
=4900
6.7 + 3.9 + 4.3 + 6.1
=(6.7+4.3)+(3.9+6.1)
=11+10
=21
2.7×4.8 + 2.7×5.2
=2.7×(4.8+5.2)
=2.7×10
=27
$\dfrac{3}{8}$÷[8×($\dfrac{3}{4}$+$\dfrac{1}{4}$)×$\dfrac{1}{8}$]
=$\dfrac{3}{8}$÷[8×1×$\dfrac{1}{8}$]
=$\dfrac{3}{8}$÷1
=$\dfrac{3}{8}$
$\dfrac{2004}{2005}$×2004
=$\dfrac{2004}{2005}$×(2005-1)
=$\dfrac{2004}{2005}$×2005 - $\dfrac{2004}{2005}$×1
=2004 - $\dfrac{2004}{2005}$
=2003$\dfrac{1}{2005}$
$\dfrac{6}{5}$÷[($\dfrac{3}{4}$-$\dfrac{2}{3}$)÷$\dfrac{5}{6}$]
=$\dfrac{6}{5}$÷[($\dfrac{9}{12}$-$\dfrac{8}{12}$)×$\dfrac{6}{5}$]
=$\dfrac{6}{5}$÷[$\dfrac{1}{12}$×$\dfrac{6}{5}$]
=$\dfrac{6}{5}$÷$\dfrac{1}{10}$
=$\dfrac{6}{5}$×10
=12
$\dfrac{5}{18}$×18 - 5×$\dfrac{4}{7}$
=5 - $\dfrac{20}{7}$
=$\dfrac{35}{7}$ - $\dfrac{20}{7}$
=$\dfrac{15}{7}$
（或写成$2\dfrac{1}{7}$）
=(201 - 147)×27
=54×27
=1458
(7.5 + 2.5×4.6)÷0.25
=(7.5 + 11.5)÷0.25
=19÷0.25
=76
84÷[($\dfrac{5}{6}$-$\dfrac{3}{4}$)×4+$\dfrac{3}{5}$]
=84÷[($\dfrac{10}{12}$-$\dfrac{9}{12}$)×4+$\dfrac{3}{5}$]
=84÷[$\dfrac{1}{12}$×4+$\dfrac{3}{5}$]
=84÷[$\dfrac{1}{3}$+$\dfrac{3}{5}$]
=84÷[$\dfrac{5}{15}$+$\dfrac{9}{15}$]
=84÷$\dfrac{14}{15}$
=84×$\dfrac{15}{14}$
=90
25×49×4
=25×4×49
=100×49
=4900
6.7 + 3.9 + 4.3 + 6.1
=(6.7+4.3)+(3.9+6.1)
=11+10
=21
2.7×4.8 + 2.7×5.2
=2.7×(4.8+5.2)
=2.7×10
=27
$\dfrac{3}{8}$÷[8×($\dfrac{3}{4}$+$\dfrac{1}{4}$)×$\dfrac{1}{8}$]
=$\dfrac{3}{8}$÷[8×1×$\dfrac{1}{8}$]
=$\dfrac{3}{8}$÷1
=$\dfrac{3}{8}$
$\dfrac{2004}{2005}$×2004
=$\dfrac{2004}{2005}$×(2005-1)
=$\dfrac{2004}{2005}$×2005 - $\dfrac{2004}{2005}$×1
=2004 - $\dfrac{2004}{2005}$
=2003$\dfrac{1}{2005}$
$\dfrac{6}{5}$÷[($\dfrac{3}{4}$-$\dfrac{2}{3}$)÷$\dfrac{5}{6}$]
=$\dfrac{6}{5}$÷[($\dfrac{9}{12}$-$\dfrac{8}{12}$)×$\dfrac{6}{5}$]
=$\dfrac{6}{5}$÷[$\dfrac{1}{12}$×$\dfrac{6}{5}$]
=$\dfrac{6}{5}$÷$\dfrac{1}{10}$
=$\dfrac{6}{5}$×10
=12
$\dfrac{5}{18}$×18 - 5×$\dfrac{4}{7}$
=5 - $\dfrac{20}{7}$
=$\dfrac{35}{7}$ - $\dfrac{20}{7}$
=$\dfrac{15}{7}$
（或写成$2\dfrac{1}{7}$）
2. 解方程。
$4 + 0.7x = 102$
$2(x - 4) = 12$
$4 + 0.7x = 102$
$2(x - 4) = 12$
答案
解方程：$4 + 0.7x = 102$
解：
$0.7x = 102 - 4$
$0.7x = 98$
$x = 98 ÷ 0.7$
$x = 140$
解方程：$2(x - 4) = 12$
解：
$x - 4 = 12 ÷ 2$
$x - 4 = 6$
$x = 6 + 4$
$x = 10$
解：
$0.7x = 102 - 4$
$0.7x = 98$
$x = 98 ÷ 0.7$
$x = 140$
解方程：$2(x - 4) = 12$
解：
$x - 4 = 12 ÷ 2$
$x - 4 = 6$
$x = 6 + 4$
$x = 10$
