8x³ - 8y³ = 8(x³ - y³) = 8(x - y)(x² + xy + y²)
(7/2-1/2):3/4-5:(1/3-1/8)=(7/8-4/8):3/4-5:(8/24-3/24)=38/:3/4-5:5/24=3/8*4/3-5*24/5=1,2-24=-23,5
(4+ab-b²)+2(a-b)²= 4ab-b²+2·a²-2ab+b²=2a²+2ab=2a(a+b)
2х-4=3х+5
-3х+2х=5+4
-3х+2х=9
-1х=9
Х=9:(-1)
Х=-9
Решение
y = x² - 6x - 7
x = 0
y = - 7