Question

[nguyen thanh tung]

cho hai so thap phan Ava B.neu them moi so 2,97thi ta duoc hai so co ty so la3,neu bot o moi so di 6,43 thi ta duoc hai so moi co ty so la 4. tim hai so A va B

Answer 1

[Đinh Thùy Linh]

Ta có: \(\hept{\begin{cases}\frac{A+2,97}{B+2,97}=3\Rightarrow A-3B=5,94\left(1\right)\\\frac{A-6,43}{B-6,43}=4\Rightarrow4B-A=19,29\left(2\right)\end{cases}}\)

Từ (1) Thay A = 5,94 + 3B vào (2) => 4B - 5,94 -3B = 19,29 => B = 19,29+5,94 = 25,23

A = 5,94 + 3*25,23 = 81,63.