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/ 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
Tính hợp lí : (112/13.20+112/20.27+...+112/62.69):(-5/9.13-7/9.25-13/19.25-31/19.69)
\(\left(\frac{112}{13.20}+\frac{112}{20.27}+\frac{112}{27.34}+....+\frac{112}{62.69}\right):\left(-\frac{5}{9.13}-\frac{7}{9.25}-\frac{13}{19.25}-\frac{31}{19.69}\right)\)
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)
B=\(\left(\frac{112}{13.20}+\frac{112}{20.27}+\frac{112}{27.34}+.........+\frac{112}{62.69}\right):\left(\frac{-5}{9.13}-\frac{7}{9.25}-\frac{13}{19.25}-\frac{31}{19.69}\right)\)
\(=\left[16\cdot\left(\dfrac{1}{13}-\dfrac{1}{20}+\dfrac{1}{20}-\dfrac{1}{27}+...+\dfrac{1}{62}-\dfrac{1}{69}\right)\right]:\dfrac{-112}{897}\)
\(=16\left(\dfrac{1}{13}-\dfrac{1}{69}\right)\cdot\dfrac{-897}{112}\)
\(=-\dfrac{897}{7}\cdot\dfrac{56}{897}=-8\)
Tính hợp lí:
\(C=\left(\frac{112}{13.20}+\frac{112}{20.27}+\frac{112}{27.34}+...+\frac{112}{62.69}\right):\left(-\frac{5}{9.13}-\frac{7}{9.25}-\frac{13}{19.25}-\frac{31}{19.69}\right)\)
Tình hợp lí
C=(11213.20 +11220.27 +11227.34 +...+11262.69 ):(−59.13 −79.25 −1319.25 −3119.69 )
Tính :
\(\left(\dfrac{112}{13.20}+\dfrac{112}{20.27}+\dfrac{112}{27.34}+...+\dfrac{112}{62.69}\right):\left(-\dfrac{5}{9.13}-\dfrac{7}{9.25}-\dfrac{13}{19.25}-\dfrac{31}{19.69}\right)\)
\(\left(\frac{112}{13.20}+\frac{112}{20.27}+\frac{112}{27.34}+...+\frac{112}{62.69}\right)\) \(:\left(-\frac{5}{9.13}-\frac{7}{9.25}-\frac{13}{19.25}-\frac{31}{19.69}\right)\)