cho a,b ∈ Z , b $\neq$ 0 . So sánh $\frac{a}{b}$ và $\frac{a + 2020}{b + 2020}$ 10/09/2021 Bởi Arya cho a,b ∈ Z , b $\neq$ 0 . So sánh $\frac{a}{b}$ và $\frac{a + 2020}{b + 2020}$
$\dfrac{a+2020}{b+2020}=\frac{a}{b+2020}+\frac{2020}{b+2020}$ Mà $\dfrac{a}{b+2020}>\frac{a}{b}$ ⇒$\frac{a}{b+2020}+\frac{2020}{b+2020}>\frac{a}{b}$ ⇒$\dfrac{a+2020}{b+2020}>\frac{a}{b}$ Bình luận
Học tốt nha.
$\dfrac{a+2020}{b+2020}=\frac{a}{b+2020}+\frac{2020}{b+2020}$
Mà $\dfrac{a}{b+2020}>\frac{a}{b}$
⇒$\frac{a}{b+2020}+\frac{2020}{b+2020}>\frac{a}{b}$
⇒$\dfrac{a+2020}{b+2020}>\frac{a}{b}$