Answer:
Explanation:
21. Break the bracket out, we get : 5(2x + 3) = 5.2x + 5.3 = 10x + 15
a is exactly alike, b is a bit longer but can be simplified as 10x + 15, so answer is a and b
22. Break the bracket of b, we get : 2(2x-4) = 2.2x - 2.4 = 4x - 8
b is exactly alike, c is a bit longer but also can be simplified as 4x-8, so b and c
23. Break the bracket of c, we get : 4(3x-4) = 4.3x - 4.4 = 12x - 16, and this is the only answer that is right.
24. Break the bracket, we get : 2(6x + 1/2) = 2.6x + 2.1/2 = 12x + 1, and b is also the only right answer
So, answer for 21,22,23,24 are : a and b, b and c, c, b respectively.