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
A=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)
\(\frac{-5}{9.13}-\frac{7}{9.25}-\frac{13}{19.25}-\frac{31}{19.69}\)
\(A=\dfrac{5}{9.13}-\dfrac{7}{9.25}-\dfrac{13}{19.25}-\dfrac{31}{19.69}\)
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)
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
a.(112/13.20 + 112/ 20.27 + 112/ 27.34 + ... +112/62.69 ) : ( -5/9.13 -7/ 9.25 - 13/19.25 - 31/19.69)
Tính bằng cách hợp lí. Ai giải nhanh mình tick cho