c) 22x - 3*2x+1 = -8,
(2x)2 - 3*2*2x + 8 = 0
(2x)2 - 6"3x + 8 = 0 | faktorisieren. -2*(-4) = 8 und -2 + (-4) = -6
(2x - 4)(2x - 2) = 0
Lösungen:
2x1 -4 = 0 ==>2x1 = 4 ==> x1 = 2 , denn 22 = 4
oder
2x2 = 2 ==> x2 = 1 , denn 21 = 2
d) 3*9-x + 9x = 4 | *9x
3 + (9x)2 = 4*9x
(9x)2 - 4*9x + 3 = 0 | faktorisieren (-1)*(-3) = 3 und -1 + (-3) = -4
(9x - 3)(9x - 1) = 0
Lösungen:
9x1 = 3 ==> x1 = 1/2, denn √(9) = 3
9x2 = 1 ==> x2 = 0, denn 90 = 1