1) 3(a+2b)-a, a+3b=1.1
= 3a + 6b - a = 2a + 6b = 2(a+3b) = 1.1 * 2 = 2,2
2) 2.4(3x+5y)-4y 0.9x+y=2
= 7.2x + 12y - 4y = 7.2x + 8y = 8(0.9x + y) = 8 * 2 =16
3) 8(0.5a+3b)+8a a+2b=2.5
= 4a + 24b + 8a = 12a + 24b = 12(a+2b) = 12 * 2.5 = 30
4) 3(0.6m+5n)-3n 0.3m+2n=4
= 1.8m + 15n - 3n = 1.8m + 12n = 6(0.4, + 2n) = 6 * 4 = 24