1) (4x - 1) (2x - 3) = 0
8x² - 12x - 2x + 3 = 0
8x² - 14 x + 3 = 0
D = 196 - 4*8*3 = 196 - 96 = 100
x1 = (14+10)/16 = 24/16 = 1,5
x2 = (14-10)/16 = 4/16 = 0,25.
2) 2c(a - 3d + 4) = 2ca - 6cd + 8c.
3) (a+2)(a²-a-3) = 0
a³ - a² - 3a + 2a² - 2a - 6 = 0
a³ + a² - 6a - 6 = 0
(a + 1)(a² - 6) = 0
a + 1 = 0 или a² - 6 = 0
a = -1 a² = 6
a = +- √6
4) (4ab²-6b²b):2ab = (2b²(2a - 3b))/2ab = (b(2a-3b))/a = (2ab - 3b²)/a