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ГДЗ Алгебра 9 клас Істер НУШ
.jpg?1786901313 "ГДЗ Алгебра 9 клас Істер НУШ")
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3) (2x – 3)(2x + 3) = 3x + 1;
4x2 – 9 – 3x – 1 = 0; 4x2 – 3x – 10 = 0;
D = (–3)2 – 4 • 4 • (–10) = 9 + 160 = 169.
x1 = (3 - √169)/(2 • 4) = (3 - 13)/8 = (-10)/8 = –5/4 = –1,25;
x2 = (3 + 13)/8 = 16/8 = 2.
Відповідь: –1,25; 2.
4) x(x – 3) – (x + 2)2 = x2 – 3x;
x2 – 3x – (x2 + 4x + 4) = x2 – 3x;
x2 – 3x – x2 – 4x – 4 – x2 + 3x = 0;
–x2 – 4x – 4 = 0 |• (–1); x2 + 4x + 4 = 0;
(x + 2)2 = 0; x + 2 = 0. x = –2.
Відповідь: –2.
4x2 – 9 – 3x – 1 = 0; 4x2 – 3x – 10 = 0;
D = (–3)2 – 4 • 4 • (–10) = 9 + 160 = 169.
x1 = (3 - √169)/(2 • 4) = (3 - 13)/8 = (-10)/8 = –5/4 = –1,25;
x2 = (3 + 13)/8 = 16/8 = 2.
Відповідь: –1,25; 2.
4) x(x – 3) – (x + 2)2 = x2 – 3x;
x2 – 3x – (x2 + 4x + 4) = x2 – 3x;
x2 – 3x – x2 – 4x – 4 – x2 + 3x = 0;
–x2 – 4x – 4 = 0 |• (–1); x2 + 4x + 4 = 0;
(x + 2)2 = 0; x + 2 = 0. x = –2.
Відповідь: –2.