Сразу решение:
А1.
= x+4y+2x+5y = 3x+9y = 3(x+3y) = x+3y
12 12 12 4
A2.
=a+2b-(a-4b) = a+2b-a+4b = 6b = 3b
2c 2c 2c c
A3.
= c² + 5c+1 + 3-3c = c²+5c+1+3-3c = c²+2c+1 = 1
c³-8 c³-8 c³-8 c³-8 (c-2)(c²+2c+1) c-2
A4.
=2a-3+2-a = a-1 = 1
a²-1 (a-1)(a+1) a+1
1 = -1
-2+1
B1.
= x²-9y - 3(x-3y) = x²-9y-3(x-3y) =
-(3-x)*(-(4-y)) (3-x)(4-y) (3-x)(4-y)
= x²-9y-3x+9y = x(x-3) = x = x
(3-x)(4-y) -(x-3)(4-y) -(4-y) y-4
C1.
y= x² + 4
x-2 2-x
y= -x² +4 = (2-x)(2+x) = 2+x = x+2
2-x 2-x