2.
a) 5b - b = 5b - b = 5b + b =
12a-36 48-16a 12(a-3) 16(3-a) 12(a-3) 16(a-3)
= 4*5b+3b = 23b
48(a-3) 48a-144
б) 1 - a+b = a-b-a-b = -2b = 2b
a-b a-b a-b b-a
в) b-6 + 2 = b- 6 + 2 = b(b-6) +2(2+b) = b²-6b+4+2b =
4-b² 2b-b² (2-b)(2+b) b(2-b) b(2-b)(2+b) b(2-b)(2+b)
= b² -4b+4 = (b-2)² = b-2 = 2-b
b(2-b)(2+b) -b(b-2)(2+b) -b(2+b) b²+2b
г) (a+b)² + (a-b)² = (a+b)² + (a-b)² = a+b + a-b = a+b+a-b = 2a = 2
a²+ab a²-ab a(a+b) a(a-b) a a a a
д) x² -4 - x²+4x+4 = (x-2)(x+2) - (x+2)² = x+2 - x+2 = 0
5x-10 5x+10 5(x-2) 5(x+2) 5 5
3.
a) 10p + 3p = 10p - 3p = 7p
p-q q-p p-q p-q p-q
б) x-3 - 2 = x-3 + 2 = x-3+2 = x-1 = 1
x-1 1-x x-1 x-1 x-1 x-1
в) a + 3 = a - 3 = a-3 = 1
a²-9 9-a² a²-9 a²-9 (a-3)(a+3) a+3