Odpowiedź:
[tex]5a(a-3)-3a(a-5)=5a^2-15a-3a^2+15a=5a^2-3a^2=2a^2\\\\\\\frac{3x-6}{3}-5=\frac{\not3(x-2)}{\not3}-5=x-2-5=x-7\\\\\\\frac{3a-9b}{3}-\frac{2a-4b}{2}=\frac{\not3(a-3b)}{\not3}-\frac{\not2(a-2b)}{\not2}=a-3b-(a-2b)=a-3b-a+2b=\\\\=-3b+2b=-b\\\\\\\frac{2x+6}{2}-\frac{6x-9}{3}=\frac{\not2(x+3)}{\not2}-\frac{\not3(2x-3)}{\not3}=x+3-(2x-3)=x+3-2x+3=-x+6[/tex]
[tex]\not4^2\cdot\frac{x-7}{\not2_{1}}+\not9^3\cdot\frac{x-1}{\not3_{1}}=2(x-7)+3(x-1)=2x-14+3x-3=5x-17\\\\\\(x+7)(2x-1)=2x^2-x+14x-7=2x^2+13x-7\\\\\\(2a-1)(a+4)=2a^2+8a-a-4=2a^2+7a-4[/tex]
