[tex]zad.a\\\\\dfrac{1}{4} z+\dfrac{1}{5} z=0,9\\\\\dfrac{1}{4} z+\dfrac{1}{5} z=\dfrac{9}{10} ~~\mid \cdot 20\\\\5z+4z=18\\\\9z=18~~\mid \div 9\\\\z=2[/tex]
[tex]zad.b\\\\\dfrac{x-4}{2} =5\cdot (x+5)~~\mid \cdot 2\\\\x-4=10\cdot (x+5)\\\\x-4=10x+50\\\\x-10x=50+4\\\\-9x=54~~\mid \div (-9)\\\\x=-6[/tex]
