Question

Rozwiąż równanie :
a ) 2 + x /2 = 1 - x /3
b ) - x + 3 /5 - 1 = 3 - 5x /2
c ) - 2x-1 /9 + 4x-5 /15 = x-5

w a) ma być -2

w b) ma być 2

w c) ma być 4 5/16

Answer 1

a )

2 + x /2 = 1 - x /3  /*6

12+3x=6-2x

3x+2x=6-12

5x=-6 /:5

x=-6/5

spr.:

L=2+(-6/5:2)=2+(-6/5*1/2)=2+(-3/5)=1 2/5

P=1-(-6/5:3)=1-(-6/5*1/3)=1+2/5=1 2/5

L=P

b )

- x + 3 /5 - 1 = 3 - 5x /2  /*10

-10x+6-10=30-25x

-10x+25x=30-6+10

15x=34 /:15

x=34/15

x=2 4/15

spr.

L=-2 4/15+3/5-1=-2 4/15+9/15-1=-40/15=-2 10/15=-2 2/3

P=3-(5*2 4/15:2)=3-(5*34/15*1/2)=3-17/3=3-5 2/3=-2 2/3

L=P
c )

- 2x-1 /9 + 4x-5 /15 = x-5

-2x+4x-x=-5+1/9+3

x=-17/9

x=-1 8/9

spr.

L=-2*(-1 8/9)-1/9+4*(-1 8/9)-3=

=34/9-1/9+(-68/9)-3=-62/9=-6 8/9

P=-1 8/9-5=-6 8/9

L=P