Առաջադրանք 219.
ա) x (x2 + 5x + 6) = 0
x2 + 5x + 6 = 0
D = 25 – 46 · 1 = 1
x1 = -b2 – √D / 2a = -5 – 1 / 2 = -3
x2 = -b2 + √D / 2a = -5 + 1 / 2 = -2
x = 0
գ) -x4 – 2x³ – 3x² = 0
x² (x² – 2x + 3) = 0
x² = 0
x² – 2x + 3 = 0
x = 0
D = 16
x1 = -3
x2 = 1:
Առաջադրանք 220.
ա) 3x + 3 = 0
2x + 5 = 0
3x = -3
2x = -5
x= -1
x = -5 / 2
գ) 5 – x = 0
3x + 2 = 0
-x = -5
3x = -2
x = 5
x = -2 / 3:
դ) 7 – x = 0
6 – 9x = 0
x = 7
x = 2 / 3:
Առաջադրանք 225.
ա) x – 2 ≠ 0
x2 + 2x = 0
x ≠ 2
x (x + 2) = 0 =>
x = 0
x = -2: