Question

3x квадрат -75=0
-x квадрат+ 2х+8=0

Answer 1

3x квадрат -75=0

3x^2=75

x^2=25

x=5 

 

-x2 + 2x + 8 = 0
D = b2 - 4ac
D = 4 + 32 = 36 = 6^2

x1,2 = -b ± √D/2a
x1 = -2 + 6/-2 = - 4/2 = -2
x2 = -2 - 6/-2 = 8/2 = 4
Ответ: x1 = -2; x2 = 4