Answer:
12.9 - 22.7b
Step-by-step explanation
Given the expression 4.3(3-5b) = 1.2b
Open the bracket
4.3(3-5b) = 1.2b
4.3(3)-(4.3)(5b) = 1.2b
12.9 - 21.5b = 1.2b
12.9 - 21.5b - 1.2b
12.9 - (21.5+1.2)b
12.9 - 22.7b
Hence the required expression is 12.9 - 22.7b
