Câu hỏi của hiền phạm

Question

làm giúp mình bài 10 và bài 11

undefined

Thanh Hoàng Thanh · Accepted Answer

Bài 1:

a) 7x + 3 = 24 b) 7x + 21 = 0

<=> 7x = 21 <=> 7x = -21

<=> x = 3 <=> x = -3

Vậy x $\in\left\{3\right\}$ Vậy x $\in\left\{-3\right\}$

c) 5 - 2x = 7

<=> 2x = -2

<=> x = -1

Vậy x $\in\left\{-1\right\}$

Bài 2:

a) $\dfrac{2}{3}x-\dfrac{3}{2}x=\dfrac{5}{12}$

<=> $\dfrac{-5}{6}x=\dfrac{5}{12}< =>x=\dfrac{-1}{2}$

Vậy x $\in\left\{\dfrac{-1}{2}\right\}$

b) $\dfrac{-2}{3}x+\dfrac{1}{5}=\dfrac{3}{10}< =>\dfrac{-2}{3}x=\dfrac{1}{10}$

<=> $x=\dfrac{-3}{20}$

Vậy x $\in\left\{\dfrac{-3}{20}\right\}$

c) $\dfrac{2}{3}x-\dfrac{1}{2}=\dfrac{1}{10}< =>\dfrac{2}{3}x=\dfrac{3}{5}< =>x=\dfrac{9}{10}$

Vậy x $\in\left\{\dfrac{9}{10}\right\}$

d) $5\dfrac{4}{7}:x=13< =>\dfrac{39}{7}:x=13$

<=> x = $\dfrac{3}{7}$

Vậy x $\in\left\{\dfrac{3}{7}\right\}$

Câu trả lời: