13. Rozwiąż równania. a) (x + 3)(x + 2) - x2 = 0 b) (x – 4)(x + 5) - x2 = 3 c) x2 - (x - 3)(x - 1) = 1 -
plis szybko potrzebuję na teraz!​


Odpowiedź :

[tex]a)\\\\(x + 3)(x + 2) - x^2 = 0\\\\x^2+2x+3x+6-x^2=0\\\\5x+6=0\\\\5x=-6\ \ |:5\\\\x=-\frac{6}{5}=-1\frac{1}{5}[/tex]

[tex]b) \\\\ (x-4)(x + 5)-x^2 = 3\\\\ x^2+5x-4x-20-x^2=3\\\\x-20=3\\\\x=3+20\\\\x=23[/tex]

[tex]c)\\\\ x^2 - (x - 3)(x - 1) = 1\\\\x^2-(x^2-x-3x+3)=1\\\\x^2- x^2+x+3x-3 =1 \\\\4x=1+3\\\\4x=4\ \ |:4\\\\x=1[/tex]