(3x-1)(3x+1)-(x-1)(x+2)=8
(9х²-1)-(х²+2х-х-2)=8
9х²-1-х²-х+2=8
8х²-х+1-8=0
8х²-х-7=0
Д= 1-4*8*(-7)=225
х₁= 1-15/16=-14/16= -7/8
х₂=1+15/16=1
<span>56b+2xz-7xb-16z = 56b - 7xb - 16z + 2xz = 7b(8 - x) - 2z(8 - x) = (7b - 2z)(8 - x)</span>
27^4/3^6 : 9^2 = (3¹²/3⁶):(3⁴) = 3⁶:3⁴=3²=9