Câu hỏi của sakura Kiemono

Question

-Mấy bạn giúp mik nha vì mik học thêm môn toán lớp 7?

bài 1: Tìm x, biết:

a) l$^{x-\frac{1}{3}l=2\frac{1}{5}}$

b) $l+\frac{2}{5}l+\frac{1}{2}=3,5$

c) l$x+\frac{1}{4}l-\frac{3}{4}=5\%$

Trúc Giang · Accepted Answer

a/ $\left|x-\frac{1}{3}\right|=2\frac{1}{5}$

$\left|x-\frac{1}{3}\right|=\frac{11}{5}$

$\Rightarrow\left[{}\begin{matrix}x-\frac{1}{3}=\frac{11}{5}\x-\frac{1}{3}=\frac{-11}{5}\end{matrix}\right.$

$\Rightarrow\left[{}\begin{matrix}x=\frac{11}{5}+\frac{1}{3}\x=\frac{-11}{5}+\frac{1}{3}\end{matrix}\right.$

$\Rightarrow\left[{}\begin{matrix}x=\frac{33}{15}+\frac{5}{15}\x=\frac{-33}{15}+\frac{5}{15}\end{matrix}\right.$

$\Rightarrow\left[{}\begin{matrix}x=\frac{38}{15}\x=\frac{28}{15}\end{matrix}\right.$

Vậy:

c/

$\left|x+\frac{1}{4}\right|-\frac{3}{4}=5\%$

$\left|x+\frac{1}{4}\right|-\frac{3}{4}=\frac{1}{20}$

$\left|x+\frac{1}{4}\right|=\frac{1}{20}+\frac{15}{20}$

$\left|x+\frac{1}{4}\right|=\frac{4}{5}$

$\Rightarrow\left[{}\begin{matrix}x+\frac{1}{4}=\frac{4}{5}\x+\frac{1}{4}=\frac{-4}{5}\end{matrix}\right.$

Bạn tự tính tiếp nhé!Câu trả lời: a/ $\left|x-\frac{1}{3}\right|=2\frac{1}{5}$