Question

Rozwiąż równania :

a) x/2= 2/5 (4-x ) -4

b)2x-1/5 - x-2/2=0,7 x

c) 2x -3x + 5 / 4 =- 1/4x - 1

Answer 1

a) x/2 = 8/5 -2/5x-4

x/2+2/5x=8/5-4 /*10

5x+4x=16-40

9x=24

x=24/9

 

b) 2x-1/5-x-1=7/10x

2x-x-7/10x=1/5+1 /*10

20x-10x-7x=2+10

x=4

 

c) 2x-3x+1/4x=-1-5/4 /*4

8x-12x+x=-4-5

-3x=-9 /:(-3)

x=3

Answer 2

a) x/2= 2/5 (4-x )-4  /*10

5x= 4(4-x)-40

5x=16-4x-40

5x+4x=16-40

9x=-24 /:9

x=-2 6/9

 

b) 2x-0,2-x-1=0,7x

2x-x-0,7x=0,2+1

0,3x=1,2 /:0,3

x=4

 

c) 2x -3x + 5/4 =- 1/4x-1 /*4

8x-12x+5=-1x-1

8x-12x+x=-1-5

-3x=-6 /:(-3)

x=2