1)
а) 1 2/5 - 1/4 = 7/5 - 1/4 = 28/20 - 5/20 = 23/20 = 1,15 - Ответ: 3)
б) 16 : 40 = 0,4 - Ответ: 1)
в) 3 4/5 - 2 1/4 = 19/5 - 9/4 = 76/20 - 45/20 = 31/20 = 1,55 - Ответ: 2)
2)
x⁻⁷/x¹⁰*x⁻² = x⁻⁷/x⁸ = 1/x = x⁻¹
3)
(x + 8)² = (x + 3)²
x² + 16x + 64 = x² + 6x + 9
10x = 9 - 64
10x = -55
x = -5.5