6(1/4x-2) =18 szybko ...

3:2x - 12=18 3:2x=30 :3:2 x=20

6(1/4x-2) =18 1½x-12=18 1½x=18+12 1½x=30 x=15

6(1/4x-2) =18 3/2x - 12=18 3/2x=18+12 3/2x=30 / : 3/2 x=30 * 2/3 x=20 ;))