1) 3(a+2b)-a = 3a + 6b - a = 2a+6b = 2(a+3b); a+3b = 1,1 , значит 2 * (1,1) = 2,2
2)2,4(3x+5y)-4y = 7,2x + 12y - 4y = 7,2 x + 8y = 8(0,9 x + y) = 8*2 = 16
3) 8(0,5a +3b) + 8a = 4a + 24b + 8a = 12a + 24 b = 12(a+2b) = 12*2,5 = 30
4) 3(0,6m + 5 n) - 3n = 1,8m + 15n - 3n = 1,8m + 12n = 6(0,3m+2n) = 6*4 = 24