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

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

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

the third picture

step-by-step explanation:

3/4 ÷ 3/4

step-by-step explanation:

basically divide any proper fraction with itself to fit the criteria.

so if we are using 3/4, then:

3/4 ÷ 3/4 = 1

so 1 is the quotient.

and the numerators for both these fractions is 3.   and if we divide the numerators:

3 ÷ 3 = 1

we see that quotient is equal to our original quotient as well.