1 вариант
1)2(х - 7у + 3z) = 2x - 14y + 6z
2)-7(5 - a - 4b) = -35 + 7a + 28b
3)9a + 9b = 9(a + b)
4)4xy + 5xy - x = 9xy - x = x(9y - 1)
5)8x - 4(16 - 2x) = 4(-2x - 16 - 2x) = 4(-16) = -64
6)-(7,2 - y) + (-y + 1,6) = -7,2 + y - y + 1,6 = -7,2 + 1,6 = -5,6
7)4a - a + b - 26b = 3a - 25b
8)1,5(8x - 6y) - 2,4(5y - 3x) = 12x - 9y - 12x + 7,2 = -1,8y
9)9/16(5(1/3)m - 2/3n) - 7/20(2(6/7)m - 5(5/7)n) = 9/16(16/3m - 2/3n) - 7/20(20/7m - 40/7n) = 3m - 6n - m + 2n = 2m - 4n
10)0,4(6x - 12) - 0,4(3x - 7) = 0,4(6x - 12 - 3x + 7) = 0,4(3x - 5) = 1,2x - 2 = 1,2 × 4(1/6) - 2 = 5 - 2 = 3
2 вариант
1) 3(2a + b - 8c) = 6a + 3b - 24c
2)-4(-x + 3y - 4z) = 4x - 12y + 16z
3)8m - 8n = 8(m - n)
4)7xy - 2xy + x = 5xy + x = x(5y + 1)
5)9y - 5(17 - 3y) = 5(1,8y - 17 - 3y) = 5(-1,2y -17) = -6y - 85
6)-(8,8 - x) + (-x + 4,7) = -8,8 + x - x + 4,7 = -4,1
7)18x - x + y - 4,5y = 17x - 3,5y
8)2,5(4x - 8y) - 1,4(5y - 3x) = 10x - 20y - 7y + 4,2x = 14,2x - 27y
9)8/9(2(1/4)a - 3/4b) - 7/30(4(2/7)a - 8(4/7)b) = 8/9(9/4a - 3/4b) - 7/30(30/7a - 60/7b) = 2a - 2/3b - a + 2b = a + 1(1/3)
10)0,6(4y - 18) - 0,4(5 - 7y) = 2,4y - 10,8 - 2 + 2,8y = 5,2y - 12,8
2)36-16=20
3)36-20=16
4)16+20=36