1 zadanie a)x² - 2x=0 x( x -2) = 0 x = 0 lub x-2 = 0 x = 0 lub x = 2 b) 3x² + 8x = 0 x( 3x + 8) = 0 x = 0 lub 3x +8 = 0 x = 0 lub 3x = -8 x = 0 lub x = -8/3 c) 4x² - x/2 =0 /*2 8x² -x = 0 x( 8x -1) = 0 x = 0 lub 8x -1 = 0 x = 0 lub x = 1/8 d) x² = -7x x² + 7x = 0 x( x +7) = 0 x = 0 lub x +7 = 0 x = 0 lub x = -7 2 zadanie ½x² = 9 /*2 x² = 18 x = ±√8 x = ±√4*√2 x = ±2√2 2x² - 1= 17 2x² = 17 +1 2x² = 18 /:2 x² = 9 x² -9 = 0 (x-3)(x+3) = 0 x -3 = 0 lub x+3 = 0 x = 3 lub x = -3 6x²- 1⅗ = 0 6x² - 8/5 = 0 2(3x² -4/5) = 0 /:2 3x² -4/5 = 0 x² = 4/5 :3 x² = 4/5*1/3 x² = 4/15 x= ±√(4/15) x = (± √2 : √15)*(√15:√15) x = ± √2*√15 :15 x = ± √30 : 15 1 - 2x² = 5+x² -2x² -x² = 5 -1 -3x² = 4 x² = -4/3 nie ma takiej liczby , która podniesiona do kwadratu dawałaby liczbe ujemną 12 - 3x²=0 3(4 -x²) = 0 /:3 4 -x² = 0 (2 -x) (2 +x) = 0 2-x = 0 lub 2 +x = 0 x = 2 lub x = -2 6x² = 8-x² 6x² +x² =8 7x² =8 x² = 8/7 x = ±√(8/7 x = ± √8 : √7 x = ± √4*√2 : √7 x = ±( 2√2 :√7)*(√7 : √7) x = ± 2√2*√7 :7 x = ±2√14 :7 x = ± 2/7*√14
