If a/ b = 6/7 and a/c = 2/5 , what is the value of 3b+c in terms of a?

Mathematics

2 answers:

Nookie1986 [14]3 years ago

6 0

Not sure. has the same question

777dan777 [17]3 years ago

6 0

<h3>Answer: 6a</h3>

====================================================

Explanation:

Solve the first equation for b

a/b = 6/7

7a = 6b ... cross multiply

6b = 7a

b = 7a/6 ... divided both sides by 6

------

Solve the second equation for c

a/c = 2/5

5a = 2c

2c = 5a

c = 5a/2

------

We found that

b = 7a/6
c = 5a/2

both are in terms of a

So,

3b+c = 3(7a/6) + 5a/2

3b+c = 21a/6 + 5a/2

3b+c = 7a/2 + 5a/2

3b+c = (7a+5a)/2

3b+c = 12a/2

3b+c = 6a

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