1) 2x+4=27
2x=27-4
2x=23
x=11,5
2) 5(9-2x)=30
45-10x=30
10x=45-30
10x=15
x=1,5
3) 2(3x-7)-3(5x+4)=21x-6
6x-14-15x-12=21x-6
9x-26=21x-6
9x-21x=-6+26
-12x=20
x=-1[tex]\frac{1}{3}[/tex]
4) (5x+1)/5-(7x-2)2=2,5x+3 //*10
2(5x+1)-5(7x-2)=25x+30
10x+2-35x+10=25x+30
10x-35x-25x=30-10-2
-50x=18
x=[tex]-\frac{9}{25}[/tex]
5) (7x-31)/17=1-x //*17
7x-31=17-17x
7x+17x=17+31
24x=48
x=2
licze na naj;)
