Question

розв'язати рівняння: x²+3x-4=0; x²-4x=0;
16-x² на 2x=0

Answer 1

Объяснение:

${x}^{2} + 3x - 4 = 0 \\ d = (3 {)}^{2} - 4 \times 1 \times ( - 4) = 9 + 16 = 25 \\ \\ x1 = \frac{ - 3 + 5}{2} = \frac{ 2}{2} = 1 \\ \\ x2 = \frac{ - 3 - 5}{2} = \frac{ - 8}{2} = - 4 \\ \\ x1 = 1 \\ x2 = - 4$

${x}^{2} - 4x = 0 \\ x(x - 4) = 0 \\ x = 0 \\ x - 4 = 0 \\ x = 4 \\ \\ x1 = 0 \\ x2 = 4$