Question

4х² - 8х - 85 = 0, t = 3
Найти t*x1*x2 ÷ x1 + x2

Answer 1

4x² - 8x - 85 = 0

По теореме Виета:

x1 + x2 = - b/a = -(-8)/4 = 2

x1*x2 = c/a = -85/4

3*(-85/4) : 2 = -255/8

Answer 2

4х² - 8х - 85 = 0, t = 3

х₁+х₂=8:4=2

х₁*х₂=85:4=-21,25

3*(-21,25)/2=-63,75:2=-31,875