Question

If a:b= 1:2 then find the value of (3a+b) : (4a+ 2b)
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Answer 1

(3a + b) : (4a +2b) = 5 : 8

Explanation:

For:

`a : b = 1 : 2`

Express these ratios into fractions:

`(a)/(b) = (1)/(2)`

Simplify:

`2a = b - - - \{eqn \: (n) \}`

For:

`(3a + b) : (4a +2 b)`

Express into fractions:

`= ((3a + b))/((4a + 2b)) \\`

substitute for b as 2a from equation (n):

`= ((3a + 2a))/((4a + 4a)) \\ \\ = (5a)/(8a) \\ \\ = (5)/(8)`

express into ratios:

`= 5 : 8`