20 \sqrt{3}
Объяснение:
49 = {x}^{2} + {x}^{2} + 6x + 9 - {x}^{2} - 3x \\ {x}^{2} + 3x - 40 = 0 \\ {x}^{2} + 8x - 5x - 40 = 0 \\ x(x + 8) - 5(x + 8) = 0 \\ (x + 8)(x - 5) = 0 \\ = > cd = 5 \\ bc = 8 \\ s = 40 \times \frac{ \sqrt{3} }{2} = 20 \sqrt{3}
20 \sqrt{3}
Объяснение:
49 = {x}^{2} + {x}^{2} + 6x + 9 - {x}^{2} - 3x \\ {x}^{2} + 3x - 40 = 0 \\ {x}^{2} + 8x - 5x - 40 = 0 \\ x(x + 8) - 5(x + 8) = 0 \\ (x + 8)(x - 5) = 0 \\ = > cd = 5 \\ bc = 8 \\ s = 40 \times \frac{ \sqrt{3} }{2} = 20 \sqrt{3}