Answers

2016-08-01T19:44:23+08:00
The answer is -(2/3)
Since 
(10c + 12b - 8a) / (12a - 15c - 18b)
take common factors out
[2(5c + 6b - 4a)] / [-3(-4a + 5c +6b)]
cancel the trinomial inside the parenthesis
it leaves you with -2/3
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