1)
0,6*(4х - 12) - 0,4*(5х - 7) = 2,4х - 7,2 - 2х + 2,8 = 0,4х - 4,4,
при х = 4 1/6: 0,4 * 4 1/6 - 4,4 = 4/10 * 25/6 - 44/10 = 5/3 - 22/5 = 25/15 - 66/15 = -41/15 = -2 11/15,
2)
5 1/7*(у - 7) - 3 3/7*(14 - у) = 36/7у - 36/7*7 - 24/7*14 + 24/7у = 60/7у - 36 - 48 = 8 4/7у - 84,
при у= -0,4: 8 4/7*(-0,4) - 84 = -60/7*4/10 - 84 = 24/7 - 588/7 = -564/7 = -80 4/7