Question

Tìm nghiệm của phương trình:

A) 3x/5 + (x-1)/4=5- (3x-1)/2

B) (2x-1)/2 +(5-x)/6 =2- 3(x+1)/4

Answer 1

a) \(\frac{3x}{5} + \frac{x -1}{4}= 5 - \frac{3x - 1}{2}\)

<=> \(\frac{12x + 5(x - 1)}{20}=\frac{20 - 10(3x - 1)}{20}\)

<=> 12x + 5(x - 1) = 20 - 10(3x - 1)

<=> 12x + 5x - 5 = 20 - 30x + 10

<=> 12x + 5x + 30x = 20 + 10 + 5

<=> 47x = 35

<=> x= \(\frac{35}{47}\)

Vậy S = \(\left \{ \frac{35}{47} \right \}\)

b) \(\frac{2x - 1}{2} + \frac{5x - 6}{6}=2 - \frac{3(x + 1)}{4}\)

<=> \(\frac{6(2x - 1) + 2(5x - 6)}{12}= \frac{12 - 9(x + 1)}{12}\)

<=> 6(2x - 1) + 2(5x - 6) = 12 - 9(x + 1)

<=> 12x - 6 + 10x - 12 = 12 - 9x - 9

<=> 12x + 10x + 9x = 12 - 9 + 6 + 12

<=> 31x = 30

<=> x = \(\frac{30}{31}\)

Vậy ..............