Lời giải:
Áp dụng HĐT đáng nhớ:
\(\frac{97^3+83^3}{180}-97.83=\frac{(97+83)(97^2-97.83+83^2)}{180}-97.83\)
\(=\frac{180(97^2-97.83+83^2)}{180}-97.83=97^2-97.83+83^2-97.83\)
\(=97^2-2.97.83+83^2\)
\(=(97-83)^2=14^2=196\)
Tính nhanh: A=\(\dfrac{97^3+83^3}{180}-97\times83\)
tính nhanh (97^3+83^3)/180 -97*83
\(C=\frac{97^3+83^3}{180}-97.83\)
\(\dfrac{9}{9898}\)*x(\(\dfrac{9}{3}\)*x)99*x=93
=)))
Tính giá tri biểu thức
a,\(\frac{43^2-11^2}{\left(36,5\right)^2-\left(27,5\right)^2}\)
b, \(\frac{97^3+83^3-97,83}{180}\)
Giải phương trình:
b) \(\dfrac{7}{2}-\left(\dfrac{x}{5}-\dfrac{1}{4}\right)=\dfrac{9}{2}\)
c) (x+2) . (x-5). (x-6) (x+3) = 180
d) \(x-\dfrac{\dfrac{x}{2}-\dfrac{3+x}{4}}{2}=\dfrac{2x-\dfrac{10-7x}{3}}{2}-x-1\)
e) \(\left(\dfrac{1}{1.101}+\dfrac{1}{2.102}+........+\dfrac{1}{10.110}\right).\left(x-3\right)=\dfrac{1}{1.11}+\dfrac{1}{2.12}+.......+\dfrac{1}{100.110}\)
Tính nhanh:
B=\(2\dfrac{1}{3154}\cdot\dfrac{3}{6517}-\dfrac{3}{3154}\cdot\dfrac{6516}{6517}+\dfrac{6}{1577}-\dfrac{6}{3154\cdot6517}\)
Giải bất phương trình:
\(\dfrac{x+2}{89}+\dfrac{x+5}{86}>\dfrac{x+8}{83}+\dfrac{x+11}{80}\)
Tính:
\(\dfrac{-1}{3}.\dfrac{141}{17}-\dfrac{39}{3}.\dfrac{-1}{17}\)
