1

1. -4а³bc×1,2ab²c³ = -4×1,2×a³×a×b×b²×c×c³ = -4,8a⁴b³c⁴
2. (-3,75)b³c²×(-0,32)b²c³ = 3,75×0,32×b³×b²×c²×c³ = 1,2b^5c^5

2

1. a-7a = -6a
2. 7a+b²-3a-2b² = 4a-b²
3. 3x-(2a-x) = 3x-2a+x = 4x - 2a

3

1. 12x-6y = 6(2x-y)
2. 2ab-6bc = 2b(a-3c)
3. 9x²-12x²y³ = 3x²(3x-4y³)

4

1. 2x²(x-3y) = 2x³-6x²y
2. (2x-3y)(3y+2x) = 4x²-9y²

4

1. (1,075-0,05):0,25 = 1,025:0,25 = 4,1
2. 

5

1. (-2)³+(0,5)²×2⁴ = -8+0,25×16= -8+4 = -4