будет 9
х(х-3)=0
х 2 -3х=0
в=3 а=1 с=0
д в 2 -4ас=9-4*1*0=9
- 17,6+( -12 2/5)= - 17,6 - 12,4= - 20
- 17,2+( - 92 4/5)= - 17,2 - 92,8= - 110
4,6 : (1 2/3 - 3,2) + 1 3/8 = -1 5/8,
1) 1 2/3 - 3,2 = 5/3 - 32/10 = 50/30 - 96/30 = -46/30 = -23/15 = -1 8/15,
2) 4,6 : (-1 8/15) = -46/10 : 23/15 = -46/10 * 15/23 = -3,
3) -3 + 1 3/8 = -24/8 + 11/8 = -13/8 = -1 5/8
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(x - 1)(x - 2) + (x + 3)(x - 3) + 3x + 18 = 0
x² - 2x - x + 2 + x² - 9 + 3x + 18 = 0
2x² + 11 = 0
2x² = -11
x∉R
(3x - 5)² - 5(5 - 6x) = 0
9x² - 30x + 25 - 25 + 30x = 0
9x² = 0
x = 0
(x - 7)² + 7(2x - 14) = 0
(x - 7)² + 14(x - 7) = 0
(x - 7)(x - 7 + 14) = 0
(x - 7)(x + 7) = 0
x = ± 7