Tính:
-5/9.13 -7/9.25 - 13 / 9.25 - 31 / 19. 69
Tính
E= 5/9.13 + 7/9.25 + 13/19.25 + 31/19.69
E=5/9.13+7/9.25+13/19.25+31/19.69
Tính hợp lí : (112/13.20+112/20.27+...+112/62.69):(-5/9.13-7/9.25-13/19.25-31/19.69)
Tính hợp lí : (112/13.20+112/20.27+...+112/62.69):(-5/9.13-7/9.25-13/19.25-31/19.69)
tính :
C=(112/13.20+112/20.27+112/27.34+...+112/62.69):(-5/9.13-7/9.25-13/19.25-31/19.69)
A=112/13.20 + 112/20.27 +... +112/62.69):(-5/9.13 - -7/9.25 - 13/19.25 - 31/19.69)
tính
E=\(\frac{5}{9.13}+\frac{7}{9.25}+\frac{13}{19.25}+\frac{31}{19.39}\)
(5+7+ 13+31 )E = 1/13 - 1/9 + 1/9 - 1/25 + 1/25 - 1/19 + 1/19 - 1/39
(5+7+ 13+31 )E = 1/13 - 1/39
(5+7+ 13+31 )E = 2/39
E = 2/39 : 56
E = 2/39 x 1/56
E = 2/2.184
\(\frac{-5}{9.13}-\frac{7}{9.25}-\frac{13}{19.25}-\frac{31}{19.69}\)
Tính nhanh:
\(\frac{-5}{9.13}-\frac{7}{9.25}-\frac{-13}{19.25}-\frac{31}{19.69}\)
\(ĐặtA=\frac{-5}{9.13}-\frac{7}{9.25}-\frac{13}{19.25}-\frac{31}{19.69}\)
\(\frac{-1}{2}.A=\frac{5}{13.18}+\frac{7}{18.25}+\frac{13}{25.38}+\frac{31}{38.69}\)
\(\frac{-1}{2}.A=\frac{1}{13}-\frac{1}{18}+\frac{1}{18}-\frac{1}{25}+\frac{1}{25}-\frac{1}{38}+\frac{1}{38}-\frac{1}{69}\)
\(\frac{-1}{2}.A=\frac{1}{13}-\frac{1}{69}\)
\(\frac{-1}{2}.A=\frac{56}{897}\)
\(A=\frac{56}{897}:\left(-\frac{1}{2}\right)\)
\(A=\frac{56}{897}.\left(-2\right)\)
\(A=\frac{-112}{897}\)
Đề của bn sai nên mk sửa lại
Ủng hộ mk nha ^_^
Đặt \(A=\frac{-5}{9.13}-\frac{7}{9.25}-\frac{-13}{19.25}-\frac{31}{19.69}\)
\(\frac{A}{2}=\frac{-5}{18.13}-\frac{7}{18.25}-\frac{-13}{38.25}-\frac{31}{38.69}\)
Đến đây tự làm