D=a2-a1
d=-25-(-18)=-7
d=-7
a51=-18+50*(-7)=-18-350=-368
1)4х+1/3=5х-1/3+15
-х=15-2/3
-х=14 2/3
х=-14 2/3
2)х+3=4х+32
-3х=29
х=-29/3=-9 2/3
3)х+8=4х+1,5
6,5=3х
х=6,5/3=65/30=13/6=2 1/6
4)1/6х=1/8х+4
1/24х=4
х=6
5)х+0,25=0,2х+6
0,8х=5,75
х=5,75/0,8=575/80=115/16=7 3/16
6)1/4+1/6=5/12
(х-у)²=х²-2ху+у²
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a) 4+2q+q^2= (2+q)^2
б) x^2+6x+1=x^2+6x+1+8-8 = x^2+6x+9 - 8 = (x+3)^2 - 8
в) a^2-4a+1= a^2-4a+1 +3 - 3=a^2-4a+4 -3 = (a-2)^2-3
г) m^2-6m+9=(m-3)^2
д) 16+8p+p^2 = (4+p)^2
е) a^2-2a= a^2-2a +1 -1= (a-1)^2 -1