Question

[Phạm Thị Kim Ngân]

\(ChoA=\left[0,8.7+\left(0,8\right)^2\right]\left(1,25.7-\frac{4}{5}.1,25\right)+31,64\)

         \(B=\frac{\left(1.09-0.29\right).\frac{5}{4}}{\left(18.9-16.65\right).\frac{8}{9}}\)

Hỏi A gấp mấy lần B?

Answer 1

[Eric Võ]

\(A=\left[0,8.7\left(0,8\right)^2\right].\left(1,25.7-\frac{4}{5}.1,25\right)+31,64\)

  \(=0,8.\left(7+0,8\right).1,25.\left(7-0,8\right)+31,64\)

  \(=0,8.7,8.1,25.6,2+31,64\)

  \(=6,24.7,75+31,64\)

   \(=48,36+31,64=80\)

\(B=\frac{\left(1,09-0,29\right).\frac{5}{4}}{\left(18,9-16,65\right).\frac{8}{9}}=\frac{0,8.1,25}{2,25.\frac{8}{9}}=\frac{1}{2}\)

\(A:B=80:\frac{1}{2}=160\)

Vậy A gấp 160 lần B.