Question

8x^2+x-75=0
3x^2-11x-14=0
3x^2+11x-34=0

Answer 1

8x² + x - 75 = 0
D = 1 + 4·75·8 = 2401 = 49²
x₁ = (-1 + 49)/16 = 48/16 = 3
x₂ = (-1 - 49)/16 = -50/16 = -25/8
Ответ: x = -25/8; 3. 

3x² - 11x - 14 = 0
D = 121 + 14·4·3 = 289 = 17²
x₁ = (11 + 17)/6 = 28/6 = 14/3
x₂ = (11 - 17)/6 = -6/6 = -1
Ответ: x = -1; 14/3. 

3x² + 11x - 34 = 0
D = 121 + 4·3·34 = 529 = 23²
x₁ = (-11 + 23)/6 = 12/6 = 2
x₂ = (-11 - 23)/6 = -34/6 = -17/3
Ответ: x = -17/3; 2.