giúp em với ạ, cảm ơn mọi ngừi

Đáp án:

Giải thích các bước giải:

a) $\text{1$\dfrac{5}{27}$+$\dfrac{7}{23}+\dfrac{1}{2}$-$\dfrac{5}{27}$+$\dfrac{16}{23}$}$

= $\text{(1$\dfrac{5}{27}$-$\dfrac{5}{27}$)}$ + $\text{($\dfrac{7}{23}$+$\dfrac{16}{23}$)}$ + $\frac{1}{2}$ 

= 1+($\dfrac{5}{27}$-$\frac{5}{27}$ ) + $\frac{23}{23}$ + $\frac{1}{2}$ 

= $\text{1+1+$\dfrac{1}{2}$}$= $\text{2+$\dfrac{1}{2}$}$= $\dfrac{5}{2}$

b) $\text{2023-}$$(\dfrac{1}{3})^{2}.$ $3^{2}$ 

= $\text{2023-$\dfrac{1}{9}$.9}$

= $\text{2023-1}$= $\text{2022}$

Câu 14:

a) $\dfrac{2}{3}$+$\dfrac{7}{4}$: $\text{x}$= $\dfrac{5}{6}$

⇒ $\dfrac{7}{4}$: $\text{x}$= $\dfrac{5}{6}$-$\dfrac{2}{3}$

⇒ $\dfrac{7}{4}$: `\text{x}`= $\dfrac{1}{6}$

⇒ `\text{x}`= $\dfrac{7}{4}$: $\dfrac{1}{6}$

⇒ `\text{x}`= $\dfrac{7.6}{4}$

⇒ `\text{x}`= $\dfrac{21}{2}$

Vậy `\text{x}`= $\dfrac{21}{2}$

b) $\dfrac{1}{4}$-($\dfrac{1}{4}$+x)= 0,25

⇒ -($\dfrac{1}{4}$+x)= 0,25-$\dfrac{1}{4}$

⇒ -($\dfrac{1}{4}$+x)= 0

⇒ -$\dfrac{1}{4}$-x= 0

⇒ -x= $\dfrac{1}{4}$

⇒ x= $\dfrac{-1}{4}$

Vậy x= $\dfrac{-1}{4}$