Đáp án + Giải thích các bước giải:
$a)$
$(4\dfrac{2}{3}-2x).2\dfrac{1}{4}= 1\dfrac{1}{2} $
$(\dfrac{14}{3}-2x).\dfrac{9}{4}= \dfrac{3}{2} $
$\dfrac{21}{2}-\dfrac{18x}{4}= \dfrac{3}{2} $
$\dfrac{18x}{4}=\dfrac{21}{2}-\dfrac{3}{2}$
$\dfrac{18x}{4}=\dfrac{18}{2}$
$18x=36$
$x=2$
Vậy $x=2$
$b)$
$\dfrac{3}{5}(\dfrac{5}{3}-x)=\dfrac{3}{5}(\dfrac{2}{3}-\dfrac{1}{5})$
$\dfrac{5}{3}-x=\dfrac{2}{3}-\dfrac{1}{5}$
$-x=\dfrac{2}{3}-\dfrac{1}{5}- \dfrac{5}{3}$
$-x=-1-\dfrac{1}{5}$
$-x=-\dfrac{6}{5}$
$x=\dfrac{6}{5}$
Vậy $x=\dfrac{6}{5}$
Kiến thức áp dụng:
- $A(B-C)=AB-AC$
- $A\dfrac{B}{C}=\dfrac{A.C+B}{C}$
