1)
x²+2x-24=0
D=4+4*24=100=10²
x1=-2+10/2=4
x2=-2-12/2=-7
Ответ: 4; -7
2)
x²+5x-6=0
D=25+4*6=7²
x1=-5+7/2=1
x2=-5-7/2=-6
Ответ: 1; -6
Аn = а1 + (n - 1)d ===> d = (an - a1) / (n - 1)
d = (39 -3) / (11 - 1)
d = 36/10
d = 3.6
1)
2x - 3 (4 - x) = 5 - (x - 1)
2x - 12 + 3x = 5 - x + 1
6x = 18
x = 3
2)
5x - 6 (2x + 7) = 13 - (x + 1)
5x - 12x - 42 = 13 - x - 1
-6x = 54
x = -9
(u+s)(u-s)+(s+d)(s-d)=u²-s²+s²-d²=u²-d²=(u-d)(u+d)