1). 1,6x - 2,5 = 4,1x 2). -2x - 20 = 7x + 43
4,1x - 1,6x = -2,5 7x + 2x = -20 - 43
2,5x = -2,5 9x = -63
x = -1 x = -7
3). -16 -1,5x = 43,8 + 3,1x 5). 7·(7 + y) - 4y = 4y - 67
3,1x + 1,5x = -16 - 43,8 7y - 4y - 4y = -67 - 49
4,6x = -59,8 -y = -116
x = -13 y = 116
4). 0,9 + 7 + (-6,53k) = 12 + 0,9 - 6,73k
6,73k - 6,53k = 12,9 - 7,9
0,2k = 5
k = 25
б) 20+4(у-5)=20 + 4у - 20 = 4у
в) 0,5х=-21
х = -21/0.5
(х = -21 · 2)
х = - 42
г) -6х-12,6=0
6х = -12,6
х = -12,6/6
х = -2.1