1) 25x^2 - 100 = 025x^2 = 100x^2 = 4x = ±2
2) (x-2)(x+4) - 2x = 0x^2 + 4x - 2x - 8 - 2x = 0x^2 = 6x + 8x^2 - 6x - 8 = 0(x-4)(x+2) = 0x = 4 or x = -2
3) 3x^2 - x - x^2 = 02x^2 - x = 0x(2x - 1) = 0x = 0 or x = 1/2
4) (2x-1)^2 - 8(2x-1) + 15 = 04x^2 - 4x + 1 - 16x + 8 + 15 = 04x^2 - 20x + 24 = 0x^2 - 5x + 6 = 0(x-2)(x-3) = 0x = 2 or x = 3
1) 25x^2 - 100 = 0
25x^2 = 100
x^2 = 4
x = ±2
2) (x-2)(x+4) - 2x = 0
x^2 + 4x - 2x - 8 - 2x = 0
x^2 = 6x + 8
x^2 - 6x - 8 = 0
(x-4)(x+2) = 0
x = 4 or x = -2
3) 3x^2 - x - x^2 = 0
2x^2 - x = 0
x(2x - 1) = 0
x = 0 or x = 1/2
4) (2x-1)^2 - 8(2x-1) + 15 = 0
4x^2 - 4x + 1 - 16x + 8 + 15 = 0
4x^2 - 20x + 24 = 0
x^2 - 5x + 6 = 0
(x-2)(x-3) = 0
x = 2 or x = 3