Answer:
5(4a + 2b)
10(2a + b)
2(10a + 5b)
Explanation:
we are trying to find equations equivalent to (20a + 10b), so distribute
5(4a + 2b) = 20a +10b YES
10(2a + b) = 20a +10b YES
2(10a +5) = 20a + 10 NO
2(10a + 5b) = 20a +10b YES
5(4a - 2b) = 20a - 10b NO